Update common.php

fixed type line 37 :

 'ACP_CUSTOMCODE_INCLUDE_EXAMPLE'			=> 'To include your own croeated files, prepend the filename with <code>../../../../../../customcode/</code><p><code>&lt;!-- INCLUDE ../../../../../../customcode/my_file.html --></code></p>',
Merge pull request #1 from WiMaPe/master-edit

fix typo en language