Description of problem:
I uploaded a file(non-plugin file) via GUI and clicked "Scan For Updates". On GUI it's showing INFO message "Finished scanning for updated plugins" on GUI. however on server.log it's showing, WARN message as like follows, 

17:56:39,677 WARN  [org.rhq.enterprise.server.core.plugin.PluginDeploymentScanner] (http-/0.0.0.0:7080-4) Does not look like [/opt/applications/jon/jon-server-3.2.0.ER3/plugins/rhq-enterprise-agent-4.9.0.JON320ER3.jar.fixme] is a plugin jar -(Cause: java.lang.NullPointerException:no xml descriptor found in jar). It will be ignored. Please fix that file or remove it.

User on GUI never notice this on GUI and he/she never delete this file. We might to give a WARN message on GUI also so that user comes to know it's failed and they have to fix it or delete it.


Version-Release number of selected component (if applicable):
Version: 3.2.0.ER3
Build Number: c0742ed:cbad264
GWT Version: 2.5.0
SmartGWT Version: 3.0

How reproducible:
100%

Steps to Reproduce:
1. Navigate to "Administration-->Server Plugins"
2. Click on "Choose File"(Upload plugin), select non-plugin file and upload it.
3. click on "Scan for updates"

Actual results:
On GUI showing INFO message "Finished scanning for updated plugins"
On server.log shows WARN message "Does not look like [/opt/applications/jon/jon-server-3.2.0.ER3/plugins/rhq-enterprise-agent-4.9.0.JON320ER3.jar.fixme] is a plugin jar -(Cause: java.lang.NullPointerException:no xml descriptor found in jar). It will be ignored. Please fix that file or remove it"

Expected results:
Should show WARN message on GUI also, so that user can fix it or delete it.