fix copy&paste fail and deny subadmins to set the default qouta

settings/ajax/removeuser.php

@@ -10,7 +10,7 @@ $username = $_POST["username"];
 
 if(!OC_Group::inGroup(OC_User::getUser(), 'admin') && !OC_SubAdmin::isUserAccessible(OC_User::getUser(), $username)){
 	$l = OC_L10N::get('core');
-	self::error(array( 'data' => array( 'message' => $l->t('Authentication error') )));
+	OC_JSON::error(array( 'data' => array( 'message' => $l->t('Authentication error') )));
 	exit();
 }
 

settings/ajax/setquota.php

@@ -13,9 +13,9 @@ OCP\JSON::callCheck();
 
 $username = isset($_POST["username"])?$_POST["username"]:'';
 
-if(!OC_Group::inGroup(OC_User::getUser(), 'admin') && !OC_SubAdmin::isUserAccessible(OC_User::getUser(), $username)){
+if(($username == '' && !OC_Group::inGroup(OC_User::getUser(), 'admin')) || (!OC_Group::inGroup(OC_User::getUser(), 'admin') && !OC_SubAdmin::isUserAccessible(OC_User::getUser(), $username))){
 	$l = OC_L10N::get('core');
-	self::error(array( 'data' => array( 'message' => $l->t('Authentication error') )));
+	OC_JSON::error(array( 'data' => array( 'message' => $l->t('Authentication error') )));
 	exit();
 }
 

settings/templates/users.php

@@ -32,7 +32,7 @@ $_['subadmingroups'] = array_flip($items);
 	<div class="quota">
 		<span><?php echo $l->t('Default Quota');?>:</span>
 		<div class="quota-select-wrapper">
-			<select class='quota'>
+			<select class='quota' <?php if(!(is_array($_['subadmins']) || $_['subadmins'])) echo 'disabled="disabled"'; ?>>
 				<?php foreach($_['quota_preset'] as $preset):?>
 				<?php if($preset!='default'):?>
 				<option