[Tech] Node gets more FEC blocks than needed

[bbackde at googlemail.com]

Following SimpleProgress shows it: some threads in freenet node seems
to be started and do not finish if we have all the needed blocks:

SimpleProgress {Total=9606, FatallyFailed=2, FinalizedTotal=true, Failed=287, Su
cceeded=6411, Identifier=get-11673399350836773, Required=6404} EndMessage

Its a request with DDA enabled, not in global queue.

Reasons? Fixes? Ideas?