Have \conninfo mention the port even for local sockets.

Per discussion with David Christensen, there can be multiple
instances of PG accessible via local sockets, and you need the port
to see which one you're actually connected to.  David's original
patch worked this way, but I inadvertently ripped it out during
commit.

src/bin/psql/command.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2010, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/command.c,v 1.222 2010/07/20 03:54:19 rhaas Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/command.c,v 1.223 2010/07/20 14:14:30 rhaas Exp $
  */
 #include "postgres_fe.h"
 #include "command.h"
@@ -306,8 +306,8 @@ exec_command(const char *cmd,
 			printf("You are connected to database \"%s\" on host \"%s\" at port \"%s\" as user \"%s\".\n",
 				   db, host, PQport(pset.db), PQuser(pset.db));
 		else
-			printf("You are connected to database \"%s\" via local socket as user \"%s\".\n",
-				   db, PQuser(pset.db));
+			printf("You are connected to database \"%s\" via local socket at port \"%s\" as user \"%s\".\n",
+				   db, PQport(pset.db), PQuser(pset.db));
 	}
 
 	/* \copy */