Only use sqlapi configuration "host" if "domain" is undefined
Only use sqlapi configuration "host" if "domain" is undefined

We'll consider an empty string domain as valid (it's actually used
for testsuite).

CartoDB/Windshaft-cartodb,manueltimita/Windshaft-cartodb,CartoDB/Windshaft-cartodb,UCL-ShippingGroup/Windshaft-cartodb,UCL-ShippingGroup/Windshaft-cartodb,manueltimita/Windshaft-cartodb,CartoDB/Windshaft-cartodb,UCL-ShippingGroup/Windshaft-cartodb,manueltimita/Windshaft-cartodb,CartoDB/Windshaft-cartodb