Adjust rate-boost threshold in cyclic refresh for seg#2.
Adjust rate-boost threshold in cyclic refresh for seg#2.

Small gain in metrics (average ~0.2dB), small
reduction in rate fluctuation.

Change-Id: Id75bd89c168486f075308fb474ebd26e3bdfb85b

mbebenita/aom,shacklettbp/aom,mbebenita/aom,smarter/aom,thdav/aom,GrokImageCompression/aom,mbebenita/aom,ittiamvpx/libvpx-1,openpeer/libvpx_new,mbebenita/aom,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,mbebenita/aom,mwgoldsmith/libvpx,luctrudeau/aom,luctrudeau/aom,jmvalin/aom,ittiamvpx/libvpx-1,webmproject/libvpx,ShiftMediaProject/libvpx,jmvalin/aom,mwgoldsmith/libvpx,GrokImageCompression/aom,ittiamvpx/libvpx-1,jmvalin/aom,mwgoldsmith/vpx,thdav/aom,webmproject/libvpx,jmvalin/aom,thdav/aom,luctrudeau/aom,GrokImageCompression/aom,mbebenita/aom,openpeer/libvpx_new,smarter/aom,Topopiccione/libvpx,mwgoldsmith/vpx,mwgoldsmith/libvpx,mwgoldsmith/libvpx,openpeer/libvpx_new,openpeer/libvpx_new,smarter/aom,ittiamvpx/libvpx-1,luctrudeau/aom,ittiamvpx/libvpx-1,smarter/aom,mwgoldsmith/vpx,webmproject/libvpx,thdav/aom,thdav/aom,mwgoldsmith/vpx,GrokImageCompression/aom,openpeer/libvpx_new,luctrudeau/aom,Topopiccione/libvpx,Topopiccione/libvpx,ShiftMediaProject/libvpx,jmvalin/aom,mwgoldsmith/vpx,Topopiccione/libvpx,Topopiccione/libvpx,mwgoldsmith/libvpx,Topopiccione/libvpx,thdav/aom,mbebenita/aom,smarter/aom,luctrudeau/aom,mwgoldsmith/libvpx,shacklettbp/aom,openpeer/libvpx_new,shacklettbp/aom,GrokImageCompression/aom,mbebenita/aom,ShiftMediaProject/libvpx,webmproject/libvpx,jmvalin/aom,webmproject/libvpx,GrokImageCompression/aom,mwgoldsmith/vpx,smarter/aom,mbebenita/aom,webmproject/libvpx,shacklettbp/aom,shacklettbp/aom,ittiamvpx/libvpx-1,shacklettbp/aom