ISTWCMS-7160: fix media types test

acceptance/WcmsTestsMediaTypesCest.php

@@ -59,7 +59,7 @@ class WcmsTestsMediaTypesCest {
     $i->amOnPage('admin/structure/media/manage/uw_mt_file/fields/media.uw_mt_file.field_media_file');
     $i->seeInField(['name' => 'settings[file_directory]'], 'uploads/documents');
     $i->seeInField(['name' => 'settings[max_filesize]'], '25 MB');
-    $i->seeInField(['name' => 'settings[file_extensions]'], 'bib, csv, doc, docx, epub, gz, key, m, mw, mp3, rtf, pdf, pot, potx, pps, ppt, pptx, psd, r, tar, tex, txt, wav, xls, xlsx, zip');
+    $i->seeInField(['name' => 'settings[file_extensions]'], 'bib, csv, doc, docx, epub, gz, json, key, m, mw, mp3, rtf, pdf, pot, potx, pps, ppt, pptx, psd, r, tar, tex, txt, wav, xls, xlsx, zip');
 
     // File directory default value for Icon media type
     // is 'uploads/icons'.