QtIFW

"Update components" does not work (if no remote is defined)

Task-number: QTIFW-156

Disable the radio button in case there's no remote set. Notify
the user about invalid/ disabled repos in case there are some..

Change-Id: I2a8ba9f3e40455ed0cb8e3d23744d7a3f0f6dd4f
Reviewed-by: Niels Weber <niels.weber@digia.com>
Reviewed-by: Tim Jenssen <tim.jenssen@digia.com>