patch 8.2.4652: leaking memory if assignment fails

Problem:    Leaking memory if assignment fails.
Solution:   Clear assigned value on failure.
diff --git a/src/version.c b/src/version.c
index fdc4ae3..843affd 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4652,
+/**/
     4651,
 /**/
     4650,