perl: also mark git-contacts executable

When installing git-contacts with Meson via -Dcontrib=contacts, the default
Perl generation fails to mark it executable. As a result, "git contacts"
reports "'contacts' is not a git command."

Unlike generate-script.sh, we aren't testing the basename here; so, glob
the script name in the case arm to match wherever the input comes from.

Signed-off-by: D. Ben Knoble <ben.knoble+github@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

generate-perl.sh

@@ -30,7 +30,7 @@ sed -e '1{' \
     "$INPUT" >"$OUTPUT"
 
 case "$INPUT" in
-*.perl)
+*.perl|*git-contacts)
 	chmod a+x "$OUTPUT";;
 *)
 	;;