[rbp] Disable textbox autoscrolling while on screensaver.

If the screensaver gets activated while in a view with autoscrolling textboxes,
CPU usage can go as high as 80-85%, the temperature reaches ~71 C.
(This also causes CPUFreq governors such as "conservative" or "ondemand" to always
run at the maximum frequency.)
Merge pull request #7 from anaconda/no-autoscroll-saver

[rbp] Disable textbox autoscrolling while on screensaver.