patch 7.4.1488

Problem:    Not using key when result from hangul_string_convert() is NULL.
Solution:   Fall back to not converted string.

src/version.c

@@ -743,6 +743,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1488,
 /**/
     1487,
 /**/