Fix encoder command line parsing for layer-wise parameters

At the encoder there are long parameters like "--QP=32" and short parameters like "-q 32"

For layer parameters -lx (with x being the layer index) the encoder always assumes that -lx is followed by two parameters, which is only true for short type parameters.

This checks for "--" in the first parameter following -lx and only reads a second parameter, if "--" is not found at the beginning.

Note: This also fixes a crash when there is no or only one parameter after -lx

changed the description

merged

mentioned in commit ab95178b

mentioned in merge request !1710 (merged)