patch 9.1.0560: bindtextdomain() does not indicate an error

Problem:  bindtextdomain() does not indicate an error
          (after v9.1.509)
Solution: return false on failure (OOM).
          (Chris van Willegen)

closes: #15116

Signed-off-by: Christ van Willegen <cvwillegen@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/vim.h b/src/vim.h
index 1b64e0d..ae7458a 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -598,7 +598,7 @@
 # ifdef bindtextdomain
 #  undef bindtextdomain
 # endif
-# define bindtextdomain(x, y) // empty
+# define bindtextdomain(x, y) ""
 # ifdef bind_textdomain_codeset
 #  undef bind_textdomain_codeset
 # endif