[JM-1178] Simple fix to remove plugins even if their directory doesn't currently exist.

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/trunk@10118 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/openfire/container/PluginManager.java

@@ -1169,7 +1169,7 @@ public class PluginManager {
                 }
             }
         }
-        boolean deleted = dir.delete();
+        boolean deleted = !dir.exists() || dir.delete();
         if (deleted) {
             // Remove the JAR/WAR file that created the plugin folder
             pluginFiles.remove(dir.getName());