tjEncodeYUVPlanes(): Ignore TJFLAG_LOSSLESS TJFLAG_LOSSLESS is irrelevant to planar YUV encoding, and setting the flag caused tjEncode*() to fail with "Invalid lossless parameters" because tjEncodeYUVPlanes() passes a JPEG quality value of -1 to setCompDefaults(). This commit modifies setCompDefaults() so that it takes no action related to the jpegQual parameter unless jpegQual >= 0.