Retrigger param does not exist on old eiger1

retrigger param does not exist on old eiger1 hardware (raises 404 in the eiger dcu logs). This causes device initialisation to fail due to: https://gitlab.esrf.fr/limagroup/Lima-camera-eiger/-/blob/master/tango/Eiger.py#L122

I've commented this locally, but i guess there needs to be a switch depending on hardware version