Get rid of try except

Signed-off-by: Aaron Raimist <aaron@raim.ist>

synapse/rest/client/v1/logout.py

@@ -38,15 +38,8 @@ class LogoutRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_POST(self, request):
-        try:
         requester = yield self.auth.get_user_by_req(request)
-        except AuthError as e:
-            # this implies the access token has already been deleted.
-            defer.returnValue((e.code, {
-                "errcode": e.errcode,
-                "error": e.msg
-            }))
-        else:
+
         if requester.device_id is None:
             # the acccess token wasn't associated with a device.
             # Just delete the access token