patch 8.0.0700: segfault with QuitPre autocommand closes the window

Problem:    Segfault with QuitPre autocommand closes the window. (Marek)
Solution:   Check that the window pointer is still valid. (Christian Brabandt,
            closes #1817)
diff --git a/src/version.c b/src/version.c
index 8cbbbf7..7c1fb10 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    700,
+/**/
     699,
 /**/
     698,