fix: use App.HostName (if set) in /about

oh yeah and we're also moving that strange ternary to main.py

Signed-off-by: mctaylors <cantsendmails@mctaylors.ru>

main.py

@@ -19,6 +19,8 @@ logger = logging.getLogger(__name__)
 config = configparser.ConfigParser()
 config.read("config.ini")
 
+hostname = config.get('App', 'HostName')
+hostname = hostname if hostname != "" else config.get('App', 'Host')
 
 def main() -> None:
     validate_config()