config.c: mark die_bad_number as NORETURN

This can help avoid -Wuninitialized false positives in
git_config_int and git_config_ulong, as the compiler now
knows that we do not return "ret" if we hit the error
codepath.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

config.c

@@ -556,6 +556,7 @@ int git_parse_ulong(const char *value, unsigned long *ret)
 	return 1;
 }
 
+NORETURN
 static void die_bad_number(const char *name, const char *value)
 {
 	const char *reason = errno == ERANGE ?