Bump activemq.version in /flink-connector-activemq (#68)

Bumps `activemq.version` from 5.14.0 to 5.15.10.

Updates `activemq-client` from 5.14.0 to 5.15.10

Updates `activemq-junit` from 5.14.0 to 5.15.10

Updates `activemq-broker` from 5.14.0 to 5.15.10

Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/flink-connector-activemq/pom.xml b/flink-connector-activemq/pom.xml
index 58302aa..a19a620 100644
--- a/flink-connector-activemq/pom.xml
+++ b/flink-connector-activemq/pom.xml
@@ -35,7 +35,7 @@
 
     <!-- Allow users to pass custom connector versions -->
     <properties>
-        <activemq.version>5.14.0</activemq.version>
+        <activemq.version>5.15.10</activemq.version>
     </properties>
 
     <dependencies>