Rename setup/index.txt to setup/ivan.sh

Don't put this commit into production, it breaks the one-command web
install from Ivan's website!

Basically by renaming index.txt to ivan.sh we can replace that script
with something like the new update script that basically tells you not
to install a2server that way anymore.  The next commit will have the new
script that does that, but git doesn't realize the new script is a
complete rewrite without at least one commit where the file changes name
but doesn't disappear to track the renamed object.

install.sh

@@ -22,6 +22,6 @@ else
 fi
 
 # Run the legacy setup script for anything not yet ported
-if [[ -e "${a2sDevel}/setup/index.txt" ]]; then
-	source "${a2sDevel}/setup/index.txt" "$@"
+if [[ -e "${a2sDevel}/setup/ivan.sh" ]]; then
+	"${a2sDevel}/setup/ivan.sh" "$@"
 fi