patch 8.0.1481: clearing a pointer takes two lines

Problem:    Clearing a pointer takes two lines.
Solution:   Add vim_clear() to free and clear the pointer.
diff --git a/src/version.c b/src/version.c
index b2f1f89..0e282ab 100644
--- a/src/version.c
+++ b/src/version.c
@@ -772,6 +772,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1481,
+/**/
     1480,
 /**/
     1479,