chg: do not redirect stdout to /dev/null

Redirecting stdout to /dev/null has unwanted side effects, namely ui.write
will stop working. This patch removes the redirection code and helps chg to
pass test-bad-extension.t.

contrib/chg/chg.c

@@ -294,12 +294,6 b' static hgclient_t *connectcmdserver(stru'
 	if (pid == 0) {
 		/* do not leak lockfd to hg */
 		close(opts->lockfd);
-		/* bypass uisetup() of pager extension */
-		int nullfd = open("/dev/null", O_WRONLY);
-		if (nullfd >= 0) {
-			dup2(nullfd, fileno(stdout));
-			close(nullfd);
-		}
 		execcmdserver(opts);
 	} else {
 		hgc = retryconnectcmdserver(opts, pid);