ibusenginesimple: Enable preedit for compose keys
ibusenginesimple: Enable preedit for compose keys

BUG=https://github.com/ibus/ibus/issues/1935

ibus/ibus,ibus/ibus,fujiwarat/ibus,fujiwarat/ibus,fujiwarat/ibus,fujiwarat/ibus,ibus/ibus,ibus/ibus