Fix STUN server usage when stunServerPort isn't set and the default value is to be used

[prlanzarin]

What is the current behavior you want to change?

The stunServerPort configuration in WebRtcEndpoint.conf.ini is supposed to be an optional one since there's a DEFAULT_STUN_PORT (3478) set up in WebRtcEndpointImpl.cpp.

Expected behaviour: be able to configure only stunServerAddress if the STUN server's port is the default one (3478).

Current behaviour: if stunServerPort isn't configured and stunServerAddress is, Kurento will not set a STUN server in the NiceAgent due to a botched pair of if-else blocks in WebRtcEndpointImpl.cpp.

What is the new behavior provided by this change?

Configuring only stunServerAddress in WebRtcEndpoint.conf.ini will make KMS configure a STUN server in the NiceAgent interface with the default STUN port (3478).

How has this been tested?

Tested with the following variation of the stunServerAddress/stunServerPort configs:

• No stunServerPort, with stunServerAddress -> STUN server set in WebRtcEndpoint with $stunServerAddress:3478
• With stunServerAddress and stunServerPort: STUN server set in WebRtcEndpoint with $stunServerAddress:stunServerPort`
• With stunServerPort, no stunServerAddress -> No STUN server set in WebRtcEndpoint
• No stunServerPort, no stunServerAddress -> No STUN server set in WebRtcEndpoint

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature / enhancement (non-breaking change which improves the project)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• My change requires a change to the documentation
• My change requires a change in other repository

Checklist

• I have read the Contribution Guidelines
• I have added an explanation of what the changes do and why they should be included
• I have written new tests for the changes, as applicable, and have successfully run them locally

[jenkinskurento]

Hi there, thanks for your Pull Request!

A Kurento member needs to verify that this patch is reasonable to test. In case it is, they should write a comment with the phrase test this please. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by Kurento members will still work. Regular contributors can be whitelisted to skip this step.