Avoid to fetchSignalingSettings in onMicrophoneClick
this led to duplicated call of fetchSignalingSettings.
because it's already called from checkDevicePermissions().
From my pov it shouldn't be triggered in onMicrophoneClick() again, at least i can not think of any scenario and while testing everything worked as expected.
The duplicated call was there since ever(?), but after implementing #3216 this also caused the call duration timer to be run twice.
Signed-off-by: Marcel Hibbe <dev@mhibbe.de>