DNS-only device coloured wrongly

[ElmerLastdrager]

Scenario:

• One device
• The device does one DNS lookup only

Expected result: the device to be shown in a grey color.
Actual result: it is green. This gets corrected later when data is transmitted.

[ElmerLastdrager]

Additionally, it seems that the node (192.168.8.4 in the screenshot) is not recognised as a device at all. There is no mac address in the information, nor is it linked to the custom name of the node.

[ElmerLastdrager]

This is heavily related to #27 (i.e., this is the generalisation of #27)