Fix GF interval for non-lagged ARFs

When ARFs are enabled in non-lagged compress modes, the GF interval
was being reset to zero. Non-lagged ARF updates were enabled in commit
63ccfbd, but this incorrect GF interval caused a quality regression.

Change-Id: I615c3b493f4ce2127044f4e68d0bcb07d6b730c3
2 files changed