update level_idc setting

reviewed at : https://rbcommons.com/s/OpenH264/r/349/

update level_idc = 1b syntax.

cite from the specification:
1. for Scalable Baseline, Scalable High, and Scalable High Intra profiles.If level_idc is equal to 9, the indicated level is level 1b.

2. for the Baseline, Constrained Baseline, Main, and Extended profiles,If level_idc is equal to 11 and constraint_set3_flag is equal to 1, the indicated level is level 1b.