Revert "FELIX-6193 - Update maven-archiver + plexus-utils (#8)"

This reverts commit 12bac911c49ffb1897f6c963484f890bcc1b9615.
diff --git a/tools/maven-bundle-plugin/pom.xml b/tools/maven-bundle-plugin/pom.xml
index dabe3be..e0e57df 100644
--- a/tools/maven-bundle-plugin/pom.xml
+++ b/tools/maven-bundle-plugin/pom.xml
@@ -206,7 +206,7 @@
   <dependency>
    <groupId>org.apache.maven</groupId>
    <artifactId>maven-archiver</artifactId>
-   <version>3.5.0</version>
+   <version>2.6</version>
   </dependency>
   <dependency>
    <groupId>org.apache.maven.shared</groupId>
diff --git a/tools/maven-bundle-plugin/src/main/java/org/apache/felix/bundleplugin/BundlePlugin.java b/tools/maven-bundle-plugin/src/main/java/org/apache/felix/bundleplugin/BundlePlugin.java
index 4d190f2..54b5383 100644
--- a/tools/maven-bundle-plugin/src/main/java/org/apache/felix/bundleplugin/BundlePlugin.java
+++ b/tools/maven-bundle-plugin/src/main/java/org/apache/felix/bundleplugin/BundlePlugin.java
@@ -1074,7 +1074,7 @@
              * Grab customized manifest entries from the maven-jar-plugin configuration
              */
             MavenArchiveConfiguration archiveConfig = JarPluginConfiguration.getArchiveConfiguration( currentProject );
-            String mavenManifestText = new MavenArchiver().getManifest( currentProject, archiveConfig.getManifest() ).toString();
+            String mavenManifestText = new MavenArchiver().getManifest( currentProject, archiveConfig ).toString();
             addMavenDescriptor = addMavenDescriptor && archiveConfig.isAddMavenDescriptor();
 
             Manifest mavenManifest = new Manifest();