GDKinit: no need to check twice whether GDKnr_threads is not 0
GDKinit: no need to check twice whether GDKnr_threads is not 0

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb