[PATCH] getdomainname should be usable on SunOS with -lnsl

Jason Riedy suggests that we should be able to use getdomainname
if we properly specify which libraries to link.

Signed-off-by: Junio C Hamano <junkio@cox.net>

convert-objects.c

@@ -1,5 +1,4 @@
 #define _XOPEN_SOURCE /* glibc2 needs this */
-#define __EXTENSIONS__ /* solaris needs this */
 #include <time.h>
 #include <ctype.h>
 #include "cache.h"