Fix related to PLT originates from commit 3caddde8
Encoder crash for following case "-c cfg/encoder_randomaccess_vtm.cfg -c cfg/per-sequence/Cactus.cfg -q 58 --ConformanceWindowMode=1 -i Cactus_1920x1080_50.yuv". The suggested MR with fix solves the issue. Perhaps Xiang Li can take a look.