systemd: drop _ prefix from username

man 5 sysuses.d recommends:
It is strongly recommended to pick user and group names that are unlikely to clash with normal users created by the administrator.
A good scheme to guarantee this is by prefixing all system and group names with the underscore, and avoiding too generic names.

Looks better without underscore. wesnoth is unique enough to not clash, most daemons on Arch don't have an underscore either.

The group is created implicitely when the user is created.

changelog_entries/systemd_nobody.md

@@ -1,2 +1,2 @@
  ### Security Fixes
-   * Run wesnothd server as `_wesnoth:_wesnoth` instead of `nobody:users`, improving safety and fixing a warning message in systemd 246+
+   * Run wesnothd server as `wesnoth:wesnoth` instead of `nobody:users`, improving safety and fixing a warning message in systemd 246+

packaging/systemd/wesnothd.service.in

@@ -23,8 +23,7 @@ ExecStopPost=/bin/rm -f @FIFO_DIR@/socket
 
 SyslogIdentifier=Wesnothd@BINARY_SUFFIX@
 WorkingDirectory=@FIFO_DIR@
-User=_wesnoth
-Group=_wesnoth
+User=wesnoth
 
 # Additional security-related features
 # (when using the -c option, do not use ProtectHome)

packaging/systemd/wesnothd.service.scons.in

@@ -4,8 +4,7 @@ After=network.target
 
 [Service]
 ExecStart=%bindir/wesnothd
-User=_wesnoth
-Group=_wesnoth
+User=wesnoth
 
 [Install]
 WantedBy=multi-user.target

packaging/systemd/wesnothd.sysusers.conf.in

@@ -1,2 +1 @@
-u _wesnoth -
-g _wesnoth -
+u wesnoth - "Wesnoth multiplayer server"

packaging/systemd/wesnothd.tmpfiles.conf.in

@@ -1 +1 @@
-d @FIFO_DIR@ 0700 _wesnoth _wesnoth -
+d @FIFO_DIR@ 0700 wesnoth wesnoth -