Set locale for tmux 2.2

tmux-2.2-setlocale-ja_JP.UTF-8.txt

diff --git tmux.c tmux.c
index cf82110..d2c57b8 100644
--- tmux.c
+++ tmux.c
@@ -193,12 +193,7 @@ main(int argc, char **argv)
 	int		 opt, flags, keys;
 
 	if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL) {
-		if (setlocale(LC_CTYPE, "") == NULL)
-			errx(1, "invalid LC_ALL, LC_CTYPE or LANG");
-		s = nl_langinfo(CODESET);
-		if (strcasecmp(s, "UTF-8") != 0 &&
-		    strcasecmp(s, "UTF8") != 0)
-			errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s);
+		errx(1, "invalid LC_CTYPE");
 	}
 
 	setlocale(LC_TIME, "");