"A version must be defined either via the MANIFEST.MF 'Implementation-Version' attribute or via the plugin descriptor 'version' attribute." error in the 2.4.1 JON agent.log

Issue

• We just installed JON 2.4.1 and are now seeing the below errors in the agent.log:

  ERROR [RHQ Agent Plugin Container Restart Thread] (rhq.core.pc.plugin.PluginManager)- Plugin [Apache] at [file:/opt/jon-agent/rhq-agent/plugins/rhq-apache-plugin-3.0.1.GA.jar] could not be loaded and will therefore not be deployed.
  org.rhq.core.clientapi.descriptor.PluginTransformException: No version is defined for plugin jar [file:/opt/jon-agent/rhq-agent/plugins/rhq-apache-plugin-3.0.1.GA.jar]. A version must be defined either via the MANIFEST.MF 'Implementation-Version' attribute or via the plugin descriptor 'version' attribute.
       at org.rhq.core.clientapi.descriptor.PluginTransformer.getVersion(PluginTransformer.java:105)......