patch 8.1.0540: may evaluate insecure value when appending to option
Problem: May evaluate insecure value when appending to option.
Solution: Set the secure flag when changing an option that was previously
set insecurely. Also allow numbers for the characters from
'spelllang' that are used for LANG.vim.
diff --git a/src/version.c b/src/version.c
index a6f155f..f3889b0 100644
--- a/src/version.c
+++ b/src/version.c
@@ -793,6 +793,8 @@
static int included_patches[] =
{ /* Add new patch number below this line */
/**/
+ 540,
+/**/
539,
/**/
538,