patch 8.1.1025: checking NULL pointer after addition

Problem:    Checking NULL pointer after addition. (Coverity)
Solution:   First check for NULL, then add the column.
diff --git a/src/version.c b/src/version.c
index 2515a25..e7f3bf3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -780,6 +780,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1025,
+/**/
     1024,
 /**/
     1023,