Allow fetching content on all import types

For better consistency, allow all types of imported entries to update,
which was already the case for Firefox and Chrome.

src/Wallabag/ImportBundle/Import/InstapaperImport.php

@@ -74,8 +74,6 @@ class InstapaperImport extends AbstractImport
                 'status' => $data[3],
                 'is_archived' => $data[3] === 'Archive' || $data[3] === 'Starred',
                 'is_starred' => $data[3] === 'Starred',
-                'content_type' => '',
-                'language' => '',
                 'html' => false,
             ];
         }

src/Wallabag/ImportBundle/Import/PinboardImport.php

@@ -98,8 +98,6 @@ class PinboardImport extends AbstractImport
         $data = [
             'title' => $importedEntry['description'],
             'url' => $importedEntry['href'],
-            'content_type' => '',
-            'language' => '',
             'is_archived' => ('no' === $importedEntry['toread']) || $this->markAsRead,
             'is_starred' => false,
             'created_at' => $importedEntry['time'],

src/Wallabag/ImportBundle/Import/ReadabilityImport.php

@@ -98,8 +98,6 @@ class ReadabilityImport extends AbstractImport
         $data = [
             'title' => $importedEntry['article__title'],
             'url' => $importedEntry['article__url'],
-            'content_type' => '',
-            'language' => '',
             'is_archived' => $importedEntry['archive'] || $this->markAsRead,
             'is_starred' => $importedEntry['favorite'],
             'created_at' => $importedEntry['date_added'],

src/Wallabag/ImportBundle/Import/WallabagV1Import.php

@@ -37,8 +37,6 @@ class WallabagV1Import extends WallabagImport
             'title' => $entry['title'],
             'html' => $entry['content'],
             'url' => $entry['url'],
-            'content_type' => '',
-            'language' => '',
             'is_archived' => $entry['is_read'] || $this->markAsRead,
             'is_starred' => $entry['is_fav'],
             'tags' => '',