Fix ci build failed and nginx adduser error (#2165)

* CI build no need CHANGE_SOURCE
* fix 'adduser: group 'www-data' in use' error

travis-build.sh

@@ -30,6 +30,9 @@ if [ -n "${PHP_VERSION}" ]; then
         # memcached extension does not yet support PHP 7.3.
         sed -i -- 's/PHP_FPM_INSTALL_MEMCACHED=true/PHP_FPM_INSTALL_MEMCACHED=false/g' .env
     fi
+
+    sed -i -- 's/CHANGE_SOURCE=true/CHANGE_SOURCE=false/g' .env
+
     cat .env
     docker-compose build ${BUILD_SERVICE}
     docker images