script: rework mjpg-streamer service setup

resources/webcamd.service

@@ -0,0 +1,16 @@
+[Unit]
+Description=Starts mjpg-streamer on startup
+After=network.target
+
+[Install]
+WantedBy=multi-user.target
+
+[Service]
+Type=forking
+User=%USER%
+WorkingDirectory=/usr/local/bin
+StandardOutput=append:/var/log/webcamd.log
+StandardError=append:/var/log/webcamd.log
+ExecStart=/usr/local/bin/webcamd
+Restart=always
+RestartSec=10