Sets the **Port_spinBox** Widget.

def __Port_spinBox_set_ui(self):
        """
        Sets the **Port_spinBox** Widget.
        """

        # Adding settings key if it doesn't exists.
        self.__settings.get_key(self.__settings_section, "port").isNull() and \
        self.__settings.set_key(self.__settings_section, "port", self.__port)

        port = foundations.common.get_first_item(self.__settings.get_key(self.__settings_section, "port").toInt())
        LOGGER.debug("> Setting '{0}' with value '{1}'.".format("Port_spinBox",
                                                                port))
        self.Port_spinBox.setValue(port)
        self.__port = port