fix ETM code change label position
fix ETM code change label position

the fleet number field would be disabled but the text label would be placed beneath the reg number field. this fixes it by changing 'reg' to 'fleet_number'

the rest of the logic implemented remains untouched
jclgoodwin/bustimes.org.uk,jclgoodwin/bustimes.org.uk,jclgoodwin/bustimes.org.uk,jclgoodwin/bustimes.org.uk