patch 8.1.0886: compiler warning for NULL pointer and condition always true

Problem:    Compiler warning for adding to NULL pointer and a condition that
            is always true.
Solution:   Check for NULL pointer before adding. Remove useless "if".
            (Friedirch, closes #3913)

src/version.c

@@ -783,6 +783,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    886,
 /**/
     885,
 /**/