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)
diff --git a/src/version.c b/src/version.c
index 4f40aab..2c280af 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3999,
+/**/
     3998,
 /**/
     3997,