usock unused if HAVE_USOCK isn't defined
usock unused if HAVE_USOCK isn't defined

more unused variables for mingw porting

use mal_clients only as point, this because the capabilities of mingw's ld for
wrapping arrays isn't up to the task.

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