patch 9.0.0686: the right ALT key does not work on some MS-Windows keyboards

Problem:    The right ALT key does not work on some MS-Windows keyboards.
Solution:   Adjust the modifiers based on GetKeyState(). (Anoton Sharonov,
            closes #11300)
diff --git a/src/version.c b/src/version.c
index 391ae4d..c6c0197 100644
--- a/src/version.c
+++ b/src/version.c
@@ -700,6 +700,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    686,
+/**/
     685,
 /**/
     684,