fix(dockerfile): Use JSON array for CMD

Author: andris9

Dockerfile

@@ -17,9 +17,5 @@ RUN npm install --production
 
 COPY . .
 
-ENV WILDDUCK_APPDIR=/wildduck \
-    WILDDUCK_CONFIG=/wildduck/config/default.toml \
-    CMD_ARGS=""
-
 ENTRYPOINT ["/usr/bin/dumb-init", "--"]
-CMD node ${WILDDUCK_APPDIR}/server.js --config=${WILDDUCK_CONFIG} ${CMD_ARGS}
+CMD ["node", "/wildduck/server.js", "--config=/wildduck/config/default.toml"]