Ensure that 3PU lookup request fields actually get passed in

synapse/rest/client/v2_alpha/thirdparty.py

@@ -35,7 +35,11 @@ class ThirdPartyUserServlet(RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request, protocol):
-        fields = {} # TODO
+        fields = request.args
+        del fields["access_token"]
+
+        # TODO(paul): Some type checking on the request args might be nice
+        #   They should probably all be strings
         results = yield self.appservice_handler.query_3pu(protocol, fields)
 
         defer.returnValue((200, results))