[ticket/9556] Drop php closing tags, add trailing newline

Closing tags converted using Oleg's script.
remove-php-end-tags.py -a .

Trailing newlines added using the following where $ext is file extension.
find . -type f -name "*.$ext" -print | xargs printf "e %s\nw\n" | ed -s;

Extensions: php, css, html, js, xml.

PHPBB3-9556

phpBB/includes/functions_install.php

@@ -555,5 +555,3 @@ function adjust_language_keys_callback($matches)
 		return (!empty($lang[$matches[1]])) ? $db->sql_escape($lang[$matches[1]]) : $db->sql_escape($matches[1]);
 	}
 }
-
-?>