docker: fix JPEG configure flag in Dockerfile
docker: fix JPEG configure flag in Dockerfile

Closes: #285

Signed-off-by: Gabriel Duque <18a98c35f49808b45edadc75fb1b25ebfd4037d6@zuh0.com>

DanielnetoDotCom/YouPHPTube-Encoder,DanielnetoDotCom/YouPHPTube-Encoder