Un-break things on IPv6-less platforms.

Commit be37c2120 forgot to teach initdb about commenting out the IPv6
replication entry that it caused to exist in pg_hba.conf.sample.
Per buildfarm.

src/bin/initdb/initdb.c

@@ -1213,15 +1213,23 @@ setup_config(void)
 
 		if (err != 0 ||
 			getaddrinfo("::1", NULL, &hints, &gai_result) != 0)
+		{
 			conflines = replace_token(conflines,
 							   "host    all             all             ::1",
 							 "#host    all             all             ::1");
+			conflines = replace_token(conflines,
+							   "host    replication     all             ::1",
+							 "#host    replication     all             ::1");
+		}
 	}
 #else							/* !HAVE_IPV6 */
 	/* If we didn't compile IPV6 support at all, always comment it out */
 	conflines = replace_token(conflines,
 							  "host    all             all             ::1",
 							  "#host    all             all             ::1");
+	conflines = replace_token(conflines,
+							  "host    replication     all             ::1",
+							  "#host    replication     all             ::1");
 #endif   /* HAVE_IPV6 */
 
 	/* Replace default authentication methods */