Some small compilation fixes for 2.13 migration. (#4836)

diff --git a/common/scala/src/main/scala/org/apache/openwhisk/core/connector/Message.scala b/common/scala/src/main/scala/org/apache/openwhisk/core/connector/Message.scala
index fdd024d..4326109 100644
--- a/common/scala/src/main/scala/org/apache/openwhisk/core/connector/Message.scala
+++ b/common/scala/src/main/scala/org/apache/openwhisk/core/connector/Message.scala
@@ -357,7 +357,7 @@
 
     statusCode match {
       case Some(value) =>
-        Try { value.convertTo[BigInt].intValue() } match {
+        Try { value.convertTo[BigInt].intValue } match {
           case Failure(_)    => Some(BadRequest.intValue)
           case Success(code) => Some(code)
         }
diff --git a/common/scala/src/main/scala/org/apache/openwhisk/core/database/cosmosdb/CosmosDBArtifactStore.scala b/common/scala/src/main/scala/org/apache/openwhisk/core/database/cosmosdb/CosmosDBArtifactStore.scala
index 0ad9ab5..038c86a 100644
--- a/common/scala/src/main/scala/org/apache/openwhisk/core/database/cosmosdb/CosmosDBArtifactStore.scala
+++ b/common/scala/src/main/scala/org/apache/openwhisk/core/database/cosmosdb/CosmosDBArtifactStore.scala
@@ -365,7 +365,7 @@
     val g = f.andThen {
       case Success(queryResult) =>
         if (queryMetrics.nonEmpty) {
-          val combinedMetrics = QueryMetrics.ZERO.add(queryMetrics: _*)
+          val combinedMetrics = QueryMetrics.ZERO.add(queryMetrics.toSeq: _*)
           logging.debug(
             this,
             s"[QueryMetricsEnabled] Collection [$collName] - Query [${querySpec.getQueryText}].\nQueryMetrics\n[$combinedMetrics]")
diff --git a/common/scala/src/main/scala/org/apache/openwhisk/core/database/cosmosdb/CosmosDBSupport.scala b/common/scala/src/main/scala/org/apache/openwhisk/core/database/cosmosdb/CosmosDBSupport.scala
index 5532bf1..bcec58d 100644
--- a/common/scala/src/main/scala/org/apache/openwhisk/core/database/cosmosdb/CosmosDBSupport.scala
+++ b/common/scala/src/main/scala/org/apache/openwhisk/core/database/cosmosdb/CosmosDBSupport.scala
@@ -17,7 +17,16 @@
 
 package org.apache.openwhisk.core.database.cosmosdb
 
-import com.microsoft.azure.cosmosdb._
+import com.microsoft.azure.cosmosdb.{
+  Database,
+  DocumentCollection,
+  FeedResponse,
+  RequestOptions,
+  Resource,
+  SqlParameter,
+  SqlParameterCollection,
+  SqlQuerySpec
+}
 import com.microsoft.azure.cosmosdb.rx.AsyncDocumentClient
 import org.apache.openwhisk.common.Logging
 
diff --git a/common/scala/src/main/scala/org/apache/openwhisk/core/mesos/MesosTask.scala b/common/scala/src/main/scala/org/apache/openwhisk/core/mesos/MesosTask.scala
index a6abec4..fc42b24 100644
--- a/common/scala/src/main/scala/org/apache/openwhisk/core/mesos/MesosTask.scala
+++ b/common/scala/src/main/scala/org/apache/openwhisk/core/mesos/MesosTask.scala
@@ -97,7 +97,7 @@
       case "host"   => Host
       case _        => User(network)
     }
-    val dnsOrEmpty = if (dnsServers.nonEmpty) Map("dns" -> dnsServers.toSet) else Map.empty
+    val dnsOrEmpty = if (dnsServers.nonEmpty) Map("dns" -> dnsServers.toSet) else Map.empty[String, Set[String]]
 
     //transform our config to mesos-actor config:
     val healthCheckConfig = mesosConfig.healthCheck.map(
diff --git a/tests/src/test/scala/org/apache/openwhisk/core/database/cosmosdb/CosmosDBArtifactStoreTests.scala b/tests/src/test/scala/org/apache/openwhisk/core/database/cosmosdb/CosmosDBArtifactStoreTests.scala
index 566d2ba..a5c6fc9 100644
--- a/tests/src/test/scala/org/apache/openwhisk/core/database/cosmosdb/CosmosDBArtifactStoreTests.scala
+++ b/tests/src/test/scala/org/apache/openwhisk/core/database/cosmosdb/CosmosDBArtifactStoreTests.scala
@@ -186,7 +186,7 @@
     //would increment a counter
     if (TransactionId.metricsKamonTags) {
       RetryMetricsCollector.getCounter(CosmosDBAction.Create) match {
-        case Some(x: LongAdder) => x.snapshot(false).intValue()
+        case Some(x: LongAdder) => x.snapshot(false).intValue
         case _                  => 0
       }
     } else {