Future problem with small (< 1.0) values for max_trigger_length in coincidenceTrigger

Having small (< 1.0) values for max_trigger_length results in float
return values of method signal.trigger.triggerOnset. These values are
used as start/end positions in an array which will yield to errors in
the future. A cast to int is necessary.

To reproduce:
coincidenceTrigger(trigger_type="recstalta", thr_on=3.5, thr_off=1, stream=tmpst, thr_coincidence_sum=3, max_trigger_length=0.01, sta=0.5, lta=10)