The --speaker option does not interoperate with the --language option. Risk of Error

Created by: maxime-fily

selecting the speakers as it is done here does not look for speakers with any other information than the speaker's tag. ther is a risk that for each language the program tries to select one speaker that we had selected but only foa a given language. Instead, I recommend going for an "exclude speaker" option, i.e. work in a "black list" mode instead of a "white list" mode.