fix: Check if user has no associated email accounts. (#22355)

check that the return array does not exist, is not an array, or is empty 

http://stackoverflow.com/questions/24403732/ddg#24403771

frappe/core/doctype/user/user.js

@@ -301,7 +301,7 @@ frappe.ui.form.on("User", {
 				email: frm.doc.email,
 			},
 			callback: function (r) {
-				if (!Array.isArray(r.message)) {
+				if (!Array.isArray(r.message) || !r.message.length) {
 					frappe.route_options = {
 						email_id: frm.doc.email,
 						awaiting_password: 1,