PHP Notice "Array to string conversion" on search

Hi,

When phpBB debug is enabled, the search of Titania returns the following PHP Notice.

[phpBB Debug] PHP Notice: in file [ROOT]/phpbb/path_helper.php on line 347: Array to string conversion

How to reproduce issue?

• Go to Titania : https://www.phpbb.com/customise/db/
• Select a category : https://www.phpbb.com/customise/db/extensions-36
• Enter your keywords on the search inputbox (near to the button "New Contribution")

This will return the PHP Notice.

The 2 notices are due to the parameters `c` and `version` that are set as array in array on controller\search.php on line 277-278

So, when this 2 parameters are handled by the phpbbb\path_helper it fails because `$value` is an array and not a string value.