use acct-{user,group}/3proxy
--- a/scripts/3proxy.service.in
+++ b/scripts/3proxy.service.in
@@ -5,8 +5,8 @@ After=network.target
 
 [Service]
 Type=simple
-User=proxy
-Group=proxy
+User=3proxy
+Group=3proxy
 Environment=CONFIGFILE=@CMAKE_INSTALL_FULL_SYSCONFDIR@/3proxy/3proxy.cfg
 ExecStart=@CMAKE_INSTALL_FULL_BINDIR@/3proxy ${CONFIGFILE}
 ExecReload=/bin/kill -SIGUSR1 $MAINPID