docs(): update readme

rootfs/usr/local/bin/run.sh

@@ -9,10 +9,11 @@ if [ -d "/rainloop/data/_data_/_default_/plugins/postfixadmin-change-password" ]
 fi
 
 # Set log output to STDOUT if wanted (LOG_TO_STDOUT=true)
-if [ "$LOG_TO_STDOUT" == "true" ]; then
+if [ "$LOG_TO_STDOUT" = true ]; then
+  echo "[INFO] Logging to stdout activated"
   chmod o+w /dev/stdout
   sed -i "s/.*error_log.*$/error_log \/dev\/stdout warn;/" /etc/nginx/nginx.conf
-  echo "Logging to STDOUT activated" > /dev/stdout
+  sed -i "s/.*error_log.*$/error_log = \/dev\/stdout/" /etc/php7/php-fpm.conf
 fi
 
 # Add postfixadmin-change-password plugin