Catch config errors on reload

http2irc.py

@@ -447,7 +447,11 @@ async def main():
 	def sigusr1_callback():
 		logging.info('Got SIGUSR1, reloading config')
 		nonlocal config, irc, webserver
-		newConfig = config.reread()
+		try:
+			newConfig = config.reread()
+		except InvalidConfig as e:
+			logging.error(f'Config reload failed: {e!s}')
+			return
 		config = newConfig
 		irc.update_config(config)
 		webserver.update_config(config)