Prevent some race conditions
Prevent some race conditions

Prevent 2 race conditions that could ocour when changing blinkrate from
something to 0 and from 0 to something:
* Only cache _oldStyle if it's different than SETTING_COLOR. Maybe it stopped
  looping when the style was added.
* If we are not looping, be sure to set the style to SETTING_COLOR. This could
  make it as the oldStyle when notifications added while changing blinkrate.
  Needed to invert the toogle logic for that too.

hackedbellini/gnome-shell-notifications-alert