Update Dockerfile

Dockerfile

@@ -2,7 +2,7 @@ FROM ubuntu:18.04
 
 ARG PEERTUBE_VER=v1.1.0
 WORKDIR /var/www/peertube
-RUN useradd -m -d /var/www/peertube -s /bin/bash -p peertube peertube && passwd peertube
+RUN useradd -m -d /var/www/peertube -s /bin/bash -p peertube peertube && echo peertube | passwd peertube --stdin
 #&& chown peertube:peertube /var/www/peertube
 
 RUN $ VERSION=$(curl -s https://api.github.com/repos/chocobozzz/peertube/releases/latest | grep tag_name | cut -d '"' -f 4) && echo "Latest Peertube version is $VERSION, current version is $PEERTUBE_VER"