git sha1: 004be8d1744920f7731415971072288f9dea0b0c

There is an issue with the vector selection option widget, which causes the gradient background of the shape being reset to "color" due to some race condition in the signal connections:

0) Create a text shape
1) Select a text shape
2) Select Background tab
3) Quickly select a dynamic gradient, i.e. the one depending on the canvas colors.
4) Very quickly click on an empty area on the canvas to reset selection.
5) The text shape becomes completely white or to reset to a random color. It may happen due to two reasons:
    * the current global FG color resets to "white"
    * the shape's background is reset to "color" with random color
6) When repeating the action too many times, a safe assert in KisSignalCompressor may happen.