systemd: Set -logflags to 0, provide -no-browser flag

Syncthing should not try to start a browser when invoked by systemd.
Furthermore we do not need any timestamps in the journal as systemd
already handles this for us.

etc/linux-systemd/system/[email protected]

@@ -6,7 +6,7 @@ After=network.target
 [Service]
 User=%i
 Environment=STNORESTART=yes
-ExecStart=/usr/bin/syncthing
+ExecStart=/usr/bin/syncthing -no-browser -logflags=0
 Restart=on-failure
 RestartPreventExitStatus=1
 SuccessExitStatus=2

etc/linux-systemd/user/syncthing.service

@@ -5,7 +5,7 @@ After=network.target
 
 [Service]
 Environment=STNORESTART=yes
-ExecStart=/usr/bin/syncthing
+ExecStart=/usr/bin/syncthing -no-browser -logflags=0
 Restart=on-failure
 RestartPreventExitStatus=1
 SuccessExitStatus=2