patch 7.4.1338

Problem:    Another part of the change is missing.
Solution:   Type os_unix.c right this time.

src/version.c

@@ -747,6 +747,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1338,
 /**/
     1337,
 /**/