Fix one flaky failure test

src/test/regress/expected/failure_connection_establishment.out

@@ -105,10 +105,10 @@ SELECT name FROM r1 WHERE id = 2;
 
 -- verify a connection attempt was made to the intercepted node, this would have cause the
 -- connection to have been delayed and thus caused a timeout
-SELECT citus.dump_network_traffic();
-        dump_network_traffic
+SELECT * FROM citus.dump_network_traffic() WHERE conn=0;
+ conn |   source    |      message
 ---------------------------------------------------------------------
- (0,coordinator,"[initial message]")
+    0 | coordinator | [initial message]
 (1 row)
 
 SELECT citus.mitmproxy('conn.allow()');

src/test/regress/sql/failure_connection_establishment.sql

@@ -66,7 +66,7 @@ SELECT name FROM r1 WHERE id = 2;
 
 -- verify a connection attempt was made to the intercepted node, this would have cause the
 -- connection to have been delayed and thus caused a timeout
-SELECT citus.dump_network_traffic();
+SELECT * FROM citus.dump_network_traffic() WHERE conn=0;
 
 SELECT citus.mitmproxy('conn.allow()');