Minor patch (OAS version +documentation correction)

[Kevsy]

Fixes #144 and #145

[gunjald]

So if the Port is optional and the MSISDN is not mandatory then does it mean the API is not specific to a subscriber but the result could be also valid for other devices who may be assigned the same public IP but different port?

[Kevsy]

So if the Port is optional and the MSISDN is not mandatory then does it mean the API is not specific to a subscriber but the result could be also valid for other devices who may be assigned the same public IP but different port?

Correct, because the goal is not to identify the subscriber: it's to identify the closest MEC to the terminal. The public IP address subnet indicates which of the network Packet Gateways issued it, and since the operator knows which packet gateway is nearest to each MEC, that is sufficient to answer the API call.

[Kevsy]

Added fix to issue #148