elm win - only auto choose x11/wl based on envvar if ELM_ENGINE unset
elm win - only auto choose x11/wl based on envvar if ELM_ENGINE unset

rvandegrift/elementary,FlorentRevest/Elementary,rvandegrift/elementary,rvandegrift/elementary,tasn/elementary,rvandegrift/elementary,tasn/elementary,tasn/elementary,tasn/elementary,tasn/elementary,FlorentRevest/Elementary,FlorentRevest/Elementary,FlorentRevest/Elementary