Fix possible receive bandwidth computation imprecision.
Fix possible receive bandwidth computation imprecision.

If some late ticks occured the receive bandwidth computation could happen on a period smaller than one second causing the computed receive bandwidth to be higher that it should be.

caizw/ortp,jiangjianping/ortp,jiangjianping/ortp,Distrotech/oRTP,carpikes/ortp,carpikes/ortp,VTCSecureLLC/ortp,caizw/ortp,VTCSecureLLC/ortp,Linphone-sync/oRTP,Distrotech/oRTP,wugh7125/ortp,wugh7125/ortp,wugh7125/ortp,jiangjianping/ortp,Linphone-sync/oRTP,VTCSecureLLC/ortp,Distrotech/oRTP,Linphone-sync/oRTP,carpikes/ortp,caizw/ortp