patch 8.2.4920: MS-Windows GUI: unused variables

Problem:    MS-Windows GUI: unused variables.
Solution:   Delete the variables. (John Marriott)
diff --git a/src/version.c b/src/version.c
index c4f5655..fe62555 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4920,
+/**/
     4919,
 /**/
     4918,