Prevent unnecessary redirect when requesting users

Opening the share dialog, the frontend is requesting `/auth/users/`
which is always redirected to `/auth/users`. That's an unnecessary extra
step.

This patch makes the front-end request `/auth/users` in the first place.

frontend/src/lib/components/ShareModal.svelte

@@ -62,7 +62,7 @@
 		if (modal) {
 			modal.showModal();
 		}
-		let res = await fetch(`/auth/users/`);
+		let res = await fetch(`/auth/users`);
 		if (res.ok) {
 			let data = await res.json();
 			allUsers = data;