Load proxied listener calls in the correct class loader

This stopped plugins from being able to use awesome listener calls

Change-Id: I31204638628067954611bbd07525ed31bf92baa7
Reviewed-on: http://gerrit.dmdirc.com/2146
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Chris Smith <chris@dmdirc.com>

src/com/dmdirc/util/ListenerList.java

@@ -138,8 +138,9 @@ public class ListenerList {
      * @param listenerType The type of listener to be called
      * @return A proxy instance that can be used to call methods
      */
+    @SuppressWarnings("unchecked")
     public <T> T getCallable(final Class<T> listenerType) {
-        return (T) Proxy.newProxyInstance(getClass().getClassLoader(),
+        return (T) Proxy.newProxyInstance(listenerType.getClassLoader(),
                 new Class[] { listenerType }, new CallHandler<T>(listenerType));
     }