Fix: RPR related for JVET-AG0145
RPR gives encoder decoder mismatch. One issue was located to JVET-AG0145. A fix is provided for the encoder so that the unscaled collocated picture is used to get the actual max and min values for that picture. Otherwise the delta parameters are coded compared to 0 and 1023 (non correct max and min values) on encoder side but derived correctly on decoder side.