patch 9.0.0524: build instructions for MS-Windows are outdated

Problem:    Build instructions for MS-Windows are outdated.
Solution:   Remove instructions for old MSVC versions.
diff --git a/src/version.c b/src/version.c
index d40a598..40273fc 100644
--- a/src/version.c
+++ b/src/version.c
@@ -700,6 +700,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    524,
+/**/
     523,
 /**/
     522,