mainvolume: send StepsUpdated signal always
mainvolume: send StepsUpdated signal always

Also when call mode is enabled or new step set from dbus interface.

nemomobile/pulseaudio-module-cmtspeech-n9xx,maemo-foss/maemo-multimedia-pulseaudio-modules-meego,nemomobile/pulseaudio-module-cmtspeech-n9xx,maemo-foss/maemo-multimedia-pulseaudio-modules-meego,jusa/pulseaudio-modules-nemo,maemo-foss/maemo-multimedia-pulseaudio-modules-meego,jusa/pulseaudio-modules-nemo,jusa/pulseaudio-modules-nemo