[SECURITY] Fedora 27 Update: mosquitto-1.5.3-1.fc27

Mosquitto is an open source message broker that implements the MQ Telemetry Transport protocol version 3.1 and 3.1.1 MQTT provides a lightweight method of carrying out messaging using a publish/subscribe model. This makes it suitable for “machine to machine” messaging such as with low power sensors or mobile devices such as phones, embedded computers or micro-controllers like the Arduino.