patch 8.2.0515: some compilers cannot add to "void *"

Problem:    Some compilers cannot add to "void *".
Solution:   Cast to "char *".
diff --git a/src/version.c b/src/version.c
index f881c1f..078775c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -739,6 +739,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    515,
+/**/
     514,
 /**/
     513,