Fix DOCKER_HOST variable

dockerfiles/dind/.profile

@@ -1,5 +1,6 @@
 export PS1='\e[1m\e[31m[\h] \e[32m($(docker-prompt)) \e[34m\u@$(hostname -i)\e[35m \w\e[0m\n$ '
 alias vi='vim'
 export PATH=$PATH:/root/go/bin
+export DOCKER_HOST=""
 cat /etc/motd
 echo $BASHPID > /var/run/cwd

dockerfiles/dind/Dockerfile

@@ -15,6 +15,7 @@ RUN mkdir -p /opt && cd /opt && \
     ./configure && make install LDFLAGS=-lintl && \
     rm -rf httping-2.5
 
+ENV DOCKER_TLS_CERTDIR=""
 ENV DOCKER_CLI_EXPERIMENTAL=enabled
 ENV DOCKERAPP_VERSION=v0.6.0
 ENV COMPOSE_VERSION=1.23.2