fix(core) plugin_iterator when schema is missing
fix(core) plugin_iterator when schema is missing

Kong/kong,jerizm/kong,shiprabehera/kong,salazar/kong,icyxp/kong,beauli/kong,Kong/kong,ccyphers/kong,akh00/kong,Vermeille/kong,Kong/kong,Mashape/kong,jebenexer/kong,li-wl/kong