updated for version 7.3.999

Problem:    New regexp engine sets curbuf temporarily.
Solution:   Use reg_buf instead, like the old engine.

src/version.c

@@ -728,6 +728,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    999,
 /**/
     998,
 /**/