git:submodule-rm: Update to current .git structure

Update the function to use the current `.git/modules/` structure, by
only using the basename of the path.

I am not sure when this was changed and too lazy right now to find it
out.

.config/zsh/autoload/git/git-submodule-rm

@@ -23,7 +23,7 @@ for arg in "$@"; do
 	# argument has to exist in repo
 	[[ -e "$toplevel/$arg_from_git" ]] || continue
 	# has to be a submodule
-	[[ -e "$toplevel/.git/modules/$arg_from_git" ]] || continue
+	[[ -e "$toplevel/.git/modules/${1:t}" ]] || continue
 
 	git submodule deinit -f  "$arg"
 	echo "command rm -rf \"$toplevel/.git/modules/$arg_from_git\""