do not disable hidden submit

this allows user to press enter and the user will report validity

dashboard/src/components/ExternalLdap.vue

@@ -258,7 +258,7 @@ onMounted(async () => {
 
       <form ref="form" @submit.prevent="onSubmit()" autocomplete="off" @input="checkValidity()">
         <fieldset :disabled="editBusy" v-if="provider !== 'noop'">
-          <input style="display: none" type="submit" :disabled="editBusy || !isFormValid" />
+          <input style="display: none" type="submit" />
 
           <FormGroup :class="{ 'has-error': editError.url }">
             <label class="control-label" for="configUrlInput">{{ $t('users.externalLdap.server') }}</label>

dashboard/src/components/MailRelaySettingsItem.vue

@@ -175,7 +175,7 @@ onMounted(async () => {
 
         <form ref="form" @submit.prevent="onSubmit()" autocomplete="off" @input="checkValidity()">
           <fieldset :disabled="busy" v-if="usesExternalServer(provider)">
-            <input type="submit" style="display: none" :disabled="busy || !isFormValid"/>
+            <input type="submit" style="display: none" />
 
             <FormGroup>
               <label for="hostInput">{{ $t('email.outbound.mailRelay.host') }}</label>

dashboard/src/components/UserDialog.vue

@@ -227,7 +227,7 @@ defineExpose({
   >
     <form @submit.prevent="onSubmit()" autocomplete="off" ref="form" @input="validateForm()">
       <fieldset :disabled="busy">
-        <input type="submit" style="display: none;" :disabled="!isFormValid" />
+        <input type="submit" style="display: none;" />
 
         <div style="display: flex; justify-content: center;">
           <div style="width: 80px;">