environment: Set time zero when animations are disabled

In commit ee09c5c8 we chose to pick the minimum value in order to preserve 0 instead of replacing it with 1. While returning 0 unconditionally when animations are disabled seems the more logic thing to do, we were unsure about possible side effects. Do the change now. Since we are early in the development cycle we should be able to deal with side effects (if any) on time for the next release.