Fixed minor memory leak.

src/states_screens/dialogs/addons_loading.cpp

@@ -331,12 +331,15 @@ void AddonsLoading::stopDownload()
     // (and not uninstalling an installed one):
     if(m_download_request)
     {
-        // In case of a cancel we can't free the memory, since
-        // network_http will potentially update the request. So in
-        // order to avoid a memory leak, we let network_http free
-        // the request.
-        //m_download_request->setManageMemory(true);
+        // In case of a cancel we can't free the memory, since the 
+        // request manager thread is potentially working on this request. So 
+        // in order to avoid a memory leak, we let the request manager
+        // free the data. This is thread safe since freeing the data is done
+        // when the request manager handles the result queue - and this is
+        // done by the main thread (i.e. this thread).
+        m_download_request->setManageMemory(true);
         m_download_request->cancel();
+        m_download_request = NULL;
     };
 }   // startDownload