patch 9.0.0542: MSVC build still has support for 2012 edition

Problem:    MSVC build still has support for 2012 edition.
Solution:   Drop MSVC 2012 support. (Ken Takata, closes #11191)
diff --git a/src/version.c b/src/version.c
index 654c71c..d1ed0c4 100644
--- a/src/version.c
+++ b/src/version.c
@@ -700,6 +700,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    542,
+/**/
     541,
 /**/
     540,