Changing www root content does not require an nginx reload.
[Unit]
Description=ergo
#After=network.target
# If you are using MySQL for history storage, comment out the above line
# and uncomment these two instead (you must independently install and configure
# MySQL for your system):
Wants=mysql.service
After=network.target mysql.service
[Service]
Type=simple
User=ergo
WorkingDirectory=/var/ergo
ExecStart=/usr/local/bin/ergo run --conf /etc/ergo/config.yaml
ExecReload=/bin/kill -HUP $MAINPID
Restart=on-failure
LimitNOFILE=1048576
[Install]
WantedBy=multi-user.target