patch 8.2.3693: Coverity warns for possibly using a NULL pointer

Problem:    Coverity warns for possibly using a NULL pointer.
Solution:   Check for NULL and give an error.

src/version.c

@@ -757,6 +757,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3693,
 /**/
     3692,
 /**/