Change only affects 1 pass vbr.

Use a q value somewhat larger (~6%) than avg_frame_qindex[INTER]
as basis for active_best_quality for inter-frames.
And use the minium of this (avg_frame_qindex) and the active_worst_quality.

This reduces some overshoot in ytlive clips.
Overall small but positive average increase in metrics (up on average ~0.2%).

Change-Id: Icdbaae7872d5675fd38a13c0ec6ce0e2e3b919ce