xdebug.ini generation fails if multiple xdebug.so files are present

[rb2k]

From here

zend_extension=<%= `find /usr -name "xdebug.so" | tr -d "\n"` %>

leads to the config path being broken if there are other PHP versions installed:

root@ns508593:~# grep -rn "php5\.5" /etc/php5/conf.d/
/etc/php5/conf.d/xdebug.ini:2:zend_extension=/usr/local/php5.6/lib/php/extensions/xdebug.so/usr/local/php5.3/lib/php/extensions/xdebug.so/usr/local/php5.5/lib/php/extensions/xdebug.so/usr/lib/php5/20090626/xdebug.so