Wrong 'nextExpiration' calculation if timer execution is blocked because of overlapping period

If the execution of a timer is suppressed because of overlapping with the next timer expiration the log show a nextExpiration date that is counted forward based on the last nextExpiration and not based on the current time.

i.e.
running since 10:00:00 every 15sec
10:00:00 start runs 50sec
10:00:15/30/45 are dropped
10:00:50 start with nextExpiration 10:00:10
10:01:00 start with nextExpiration 10:00:20