subsolutions bugfix
subsolutions bugfix

fixes #307

fplll/fplll,dstehle/fplll,shi-bai/fplll,dstehle/fplll,cr-marcstevens/fplll,fplll/fplll,fplll/fplll,cr-marcstevens/fplll,dstehle/fplll,cr-marcstevens/fplll,fplll/fplll,shi-bai/fplll,shi-bai/fplll,shi-bai/fplll,fplll/fplll,cr-marcstevens/fplll