fix: info message error when using invite more option

Signed-off-by: Raju Udava <86527202+dstala@users.noreply.github.com>

packages/nc-gui-v2/components/tabs/auth/user-management/UsersModal.vue

@@ -41,7 +41,7 @@ const validators = computed(() => {
     emails: [
       {
         validator: (rule: any, value: string, callback: (errMsg?: string) => void) => {
-          if (value.length === 0) {
+          if (!value || value.length === 0) {
             callback('Email is required')
             return
           }