Fix the parameters of a test fixture (#7243)

changelog.d/7243.misc

+Correct the parameters of a test fixture. Contributed by Isaiah Singletary.

tests/rest/client/v1/test_events.py

@@ -50,7 +50,7 @@ class EventStreamPermissionsTestCase(unittest.HomeserverTestCase):
 
         return hs
 
-    def prepare(self, hs, reactor, clock):
+    def prepare(self, reactor, clock, hs):
 
         # register an account
         self.user_id = self.register_user("sid1", "pass")