patch 8.1.1106: no test for 'writedelay'

Problem:    No test for 'writedelay'.
Solution:   Add a test.
diff --git a/src/version.c b/src/version.c
index 08e2394..9fd355a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -772,6 +772,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1106,
+/**/
     1105,
 /**/
     1104,