fix NullPointerException in ITicketService and add TestCase

Kevin Walter

2014-04-14 4868740ed7f40ce0cf162f17a8224856ae10a4b0

 src/main/java/com/gitblit/manager/GitblitManager.java

@@ -1260,6 +1260,11 @@
   }

   @Override
   public boolean upgradePlugin(String pluginId, String url, boolean verifyChecksum) throws IOException {
      return pluginManager.upgradePlugin(pluginId, url, verifyChecksum);
   }

   @Override
   public List<PluginRegistration> getRegisteredPlugins() {
      return pluginManager.getRegisteredPlugins();
   }