simplify MapViewWidget::setMapThemeId()
simplify MapViewWidget::setMapThemeId()

* make code more straight-formward: first update celestial body combobox, then map theme list (the latter depends on the former)

oberluz/marble,utkuaydin/marble,probonopd/marble,oberluz/marble,oberluz/marble,tzapzoor/marble,utkuaydin/marble,Earthwings/marble,tucnak/marble,David-Gil/marble-dev,tzapzoor/marble,probonopd/marble,quannt24/marble,probonopd/marble,David-Gil/marble-dev,Earthwings/marble,probonopd/marble,David-Gil/marble-dev,rku/marble,adraghici/marble,tucnak/marble,probonopd/marble,adraghici/marble,tzapzoor/marble,adraghici/marble,rku/marble,tzapzoor/marble,AndreiDuma/marble,David-Gil/marble-dev,Earthwings/marble,oberluz/marble,Earthwings/marble,David-Gil/marble-dev,quannt24/marble,adraghici/marble,tucnak/marble,oberluz/marble,adraghici/marble,tzapzoor/marble,AndreiDuma/marble,tucnak/marble,AndreiDuma/marble,Earthwings/marble,tucnak/marble,tucnak/marble,David-Gil/marble-dev,AndreiDuma/marble,utkuaydin/marble,utkuaydin/marble,quannt24/marble,quannt24/marble,tzapzoor/marble,tucnak/marble,tzapzoor/marble,probonopd/marble,AndreiDuma/marble,rku/marble,tzapzoor/marble,probonopd/marble,AndreiDuma/marble,oberluz/marble,utkuaydin/marble,rku/marble,quannt24/marble,adraghici/marble,quannt24/marble,Earthwings/marble,rku/marble,quannt24/marble,rku/marble,utkuaydin/marble