fix: make module to export required. (#18204) (#18218)

(cherry picked from commit 5330814d7a)

Co-authored-by: Devin Slauenwhite <devin.slauenwhite@gmail.com>

frappe/custom/doctype/customize_form/customize_form.js

@@ -178,6 +178,7 @@ frappe.ui.form.on("Customize Form", {
 								fieldname: "module",
 								options: "Module Def",
 								label: __("Module to Export"),
+								reqd: 1,
 							},
 							{
 								fieldtype: "Check",