Remove unused maubot variable

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1894

roles/matrix-bot-maubot/defaults/main.yml

@@ -54,7 +54,6 @@ matrix_bot_maubot_management_interface_port: 29316
 matrix_bot_maubot_management_interface_http_bind_port: ''
 
 
-matrix_bot_maubot_port: 29316
 matrix_bot_maubot_unshared_secret: 'generate'
 
 # Specifies the default log level for all bot loggers.