Fix share warning with Wallabag (#2817)

#fix https://github.com/FreshRSS/FreshRSS/issues/2812

Co-authored-by: Frans de Jonge <fransdejonge@gmail.com>

app/Models/Share.php

@@ -260,7 +260,9 @@ class FreshRSS_Share {
 		}
 
 		foreach ($transform as $action) {
-			$data = call_user_func($action, $data);
+			if (is_string($action) && $action != '') {
+				$data = call_user_func($action, $data);
+			}
 		}
 
 		return $data;

app/shares.php

@@ -39,20 +39,14 @@ return array(
 	),
 	'wallabag' => array(
 		'url' => '~URL~?action=add&url=~LINK~',
-		'transform' => array(
-			'link' => array('base64_encode'),
-			'title' => array(),
-		),
+		'transform' => array('rawurlencode'),
 		'help' => 'http://www.wallabag.org/',
 		'form' => 'advanced',
 		'method' => 'GET',
 	),
 	'wallabagv2' => array(
 		'url' => '~URL~/bookmarklet?url=~LINK~',
-		'transform' => array(
-			'link' => array('rawurlencode'),
-			'title' => array(),
-		),
+		'transform' => array('rawurlencode'),
 		'help' => 'http://www.wallabag.org/',
 		'form' => 'advanced',
 		'method' => 'GET',