fix: 用户分配角色bug fix

vue/src/views/system/role/roleUser.vue

@@ -202,6 +202,9 @@ export default defineComponent({
     };
 
     const saveRoleUser = () => {
+      if (!targetKeys.value || targetKeys.value.length === 0) {
+        return false;
+      }
       saveRoleUserList(searchParamsState.roleID, targetKeys.value).then(() => {
         visibleUserModal.value = false;
         loadRoleUserList();