Make sure we do include "clients_config.h" in all .c files.
Make sure we do include "clients_config.h" in all .c files.

Thanks go to the compilers on Windows to detecting and reporting this error!

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