dnsdist: Consistently handle slow protobuf messages in our tests

It was not an issue before, but GH actions runners are so bad these
days that we are now encountering these errors quite often.
In any case we should have been more consistent to begin with.

Signed-off-by: Remi Gacogne <remi.gacogne@powerdns.com>

Author: rgacogne

regression-tests.dnsdist/test_OpenTelemetryTracing.py

@@ -66,12 +66,8 @@ def sendQueryAndGetProtobuf(
             self.assertTrue(receivedResponse)
             self.assertEqual(response, receivedResponse)
 
-        if self._protobufQueue.empty():
-            # let the protobuf messages the time to get there
-            time.sleep(1)
-
         # check the protobuf message corresponding to the UDP query
-        return self.getFirstProtobufMessage()
+        return self.getFirstProtobufMessage(timeout=1)
 
     def checkOTData(
         self,