Extension browser doesn't list extensions having letter x,m or l at the end of the key

For example: extension org.civicrm.sms.clickatell is not listed.

Problem is code uses trim($key, '.xml') to remove ".xml" from key.

For example following sample of code outputs "org.civicrm.sms.clickate" instead of "org.civicrm.sms.clickatell" :

$key = 'org.civicrm.sms.clickatell.xml';
echo trim($key, '.xml'); // outputs "org.civicrm.sms.clickate" and not "org.civicrm.sms.clickatell"

This is due to nature of trim function - http://php.net/manual/en/function.trim.php

This makes code not list the extensions having key ending with any of the letter from x,m,l.

Note: This happens for case when list is fetched from extension resource url.