Don't set application_name in logical replication workers

This was bothering some people because it's not the intended use of
application_name and it makes the default view of pg_stat_activity
bulky.

src/backend/replication/logical/launcher.c

@@ -803,10 +803,6 @@ ApplyLauncherMain(Datum main_arg)
 	pqsignal(SIGTERM, logicalrep_launcher_sigterm);
 	BackgroundWorkerUnblockSignals();
 
-	/* Make it easy to identify our processes. */
-	SetConfigOption("application_name", MyBgworkerEntry->bgw_name,
-					PGC_USERSET, PGC_S_SESSION);
-
 	LogicalRepCtx->launcher_pid = MyProcPid;
 
 	/*

src/backend/replication/logical/worker.c

@@ -1488,10 +1488,6 @@ ApplyWorkerMain(Datum main_arg)
 	MyLogicalRepWorker->last_send_time = MyLogicalRepWorker->last_recv_time =
 		MyLogicalRepWorker->reply_time = GetCurrentTimestamp();
 
-	/* Make it easy to identify our processes. */
-	SetConfigOption("application_name", MyBgworkerEntry->bgw_name,
-					PGC_USERSET, PGC_S_SESSION);
-
 	/* Load the libpq-specific functions */
 	load_file("libpqwalreceiver", false);