Remove reference to uninitialized variable (#3295)

Co-authored-by: narrieta@microsoft <narrieta>

tests_e2e/tests/scripts/agent_firewall-verify_all_firewall_rules.py

@@ -100,7 +100,7 @@ def _verify_dns_request_to_wireserver(should_succeed: bool) -> None:
             if succeeded:
                 raise Exception(f"Error -- unprivileged user:({current_user}) could connect to wireserver port 53, make sure the firewall rules are set correctly")
             else:
-                raise Exception(f"Cannot issue a DNS request as user '{current_user}'), make sure the firewall rules are set correctly {e}")
+                raise Exception(f"Cannot issue a DNS request as user '{current_user}'), make sure the firewall rules are set correctly [DNS request timed out]")
 
     @staticmethod
     def _verify_http_request_to_wireserver(should_succeed: bool) -> None: