patch 8.0.1501: out-of-memory situation not correctly handled

Problem:    Out-of-memory situation not correctly handled. (Coverity)
Solution:   Check for NULL value.

src/version.c

@@ -771,6 +771,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1501,
 /**/
     1500,
 /**/