Remove unneeded os-release

Dockerfile

@@ -4,7 +4,6 @@ LABEL maintainer Camptocamp "[email protected]"
 ENV \
   DEBIAN_FRONTEND=noninteractive
 RUN \
-  . /etc/os-release && \
   apt-get update && \
   apt-get install --assume-yes --no-install-recommends apt-utils && \
   apt-get install --assume-yes --no-install-recommends gettext && \
@@ -23,7 +22,6 @@ FROM base AS base-node
 
 ENV NODE_PATH=/usr/lib/node_modules
 RUN \
-  . /etc/os-release && \
   apt-get update && \
   apt-get install --assume-yes --no-install-recommends apt-transport-https && \
   echo "deb https://deb.nodesource.com/node_10.x ${VERSION_CODENAME} main" > /etc/apt/sources.list.d/nodesource.list && \
@@ -74,7 +72,6 @@ ARG MAJOR_VERSION
 ENV MAJOR_VERSION=$MAJOR_VERSION
 
 RUN \
-  . /etc/os-release && \
   apt-get update && \
   apt-get install --assume-yes --no-install-recommends libxml2-utils && \
   apt-get clean && \

doc/Dockerfile

@@ -1,10 +1,7 @@
 FROM debian
 
-RUN \
-  . /etc/os-release && \
-  apt-get update
-RUN \
-  apt-get install --assume-yes --no-install-recommends python3-pip python3-setuptools gettext
+RUN apt-get update
+RUN apt-get install --assume-yes --no-install-recommends python3-pip python3-setuptools gettext
 
 COPY requirements.txt /tmp/
 RUN \

docker/test-mapserver/Dockerfile

@@ -2,7 +2,6 @@ FROM camptocamp/mapserver:7.4
 LABEL maintainer Camptocamp "[email protected]"
 
 RUN \
-  . /etc/os-release && \
   apt-get update && \
   apt-get install --assume-yes --no-install-recommends gettext && \
   apt-get clean && \