modifiedsince endpoint is broken

[kumy]

accessing https://api.geokrety.org/gk/details/2016-06-23 raise a 404

[kumy]

• Canonical url is broken == 404
• But endpoint in itself is also broken https://api.geokrety.org/select.php?modifiedsince=20160623

<geokret date="2014-09-03" while filter is about dateupdated attribute

{ doc("geokrety-details.xml")/gkxml/geokrety/geokret[dateupdated >= $modifiedsince] }