chatview: outgoing call icon has clickable button class

The arrow icon for "Incoming call", "Outgoing call", etc. messages is a clickable button (see attached image, red zone). And there's no reason why it would ever be a clickable button. It should just be a non-clickable icon.

This is an easy bug (fix HTML/CSS code).

Hint: start Ring with gnome-ring -d and you'll have access to web developer tools by right clicking and selecting "Inspect element".