Do not attempt to select the first item in a selector if model is empty
Do not attempt to select the first item in a selector if model is empty

When switching the selection mode in a HildonTouchSelector, the first
item might be selected. When retrieving the iterator for this, make
sure that there is actually data in the model, before selecting it.

This prevents a critical warning. Reported by Iván Frade.

Cordia/libhildon,android-808/libhildon,Cordia/libhildon,android-808/libhildon,android-808/libhildon,Cordia/libhildon