vp9-rtc: Fix to usage of active_maps when aq_mode=0
vp9-rtc: Fix to usage of active_maps when aq_mode=0

If aq_mode=0 the segmentation feature may still be used
for active_maps, so the condition active_maps.enabled
needs to be added in two places regarding segmentation
logic in encodeframe.c. Otherwise the active_maps would
have no effect.

This also resolves why the assert in bug webm:1762 was
not triggered when aq_mode=0.

Change-Id: Ibd68e9b5c3f81728241a168d3fb3567d6845633d

ShiftMediaProject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx