patch 8.1.0813: FileChangedShell not sufficiently tested

Problem:    FileChangedShell not sufficiently tested.
Solution:   Add a more comprehensive test case.
diff --git a/src/version.c b/src/version.c
index 1114641..230d2fb 100644
--- a/src/version.c
+++ b/src/version.c
@@ -788,6 +788,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    813,
+/**/
     812,
 /**/
     811,