patch 8.2.3999: redundant check for NUL byte

Problem:    Redundant check for NUL byte.
Solution:   Remove the check for a NUL byte. (closes #9471)

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3999,
 /**/
     3998,
 /**/