Fix Linux first-time rendering

On Linux, the first time a screen size or theme is rendered, the wrong
image is shown (until the scene is re-rendered). The reason for this
is that the first time, the palette previews are generated. And this
has the side-effect of replacing the current render session for the
editor with the most recent render image from the palette preview.

The fix is simple: After rendering previews, trigger another render.

Change-Id: Ic00fa8b2703c4ce8ad4068412d5eea7b0b9f093c
1 file changed