GeoCoding: Fix auto commit

[janezd]

Auto commit in Geocoding does not use deferred callbacks. It has auto_commit, but does not properly handle it.

(Before #180, set_data called callback for chaning the combo value, which called commit. I forgot how the old autocommits workek, but set_data and callbacks certainly have to call a different method. In #180, this incorrect behaviour is kept as it is.)