patch 9.0.1199: crash when using kitty and using a mapping with <Esc>

Problem:    Crash when using kitty and using a mapping with <Esc>.
Solution:   Do not try setting did_simplify when it is NULL. (closes #11817)
diff --git a/src/version.c b/src/version.c
index 763c79d..2b472d3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1199,
+/**/
     1198,
 /**/
     1197,