lz4cli : removed extension artefacts
lz4cli : removed extension artefacts

It used to be useful for an old Windows variant which is no longer maintained.

unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso