bugfix CU/DU: use correct IP address for GTP-U

Not only the teid is received from the DU but also the IP address. We have to use it too.

Also, don't connect the UDP socket. The parameter remote_s_address in the configuration file must not be used, at least not for gtp-u because the IP address is received from the DU (plus for later, for multiple DUs, it won't work at all).

added 5G-NR label

OAI RAN-Container-Parent build (3688): failed (https://jenkins-oai.eurecom.fr/job/RAN-Container-Parent/3688/)

requested review from @lthomas

I fully agree:

• update tunnels would have to change Teid and also address
• we should use the protocol embedded information elements when we have it instead of configuration file

For me, we should soon make more: remove all this "init", "instance" in gtp to use embedded data automatically

changed milestone to %REVIEW_COMPLETED_AND_APPROVED

changed milestone to %OK_TO_BE_MERGED

mentioned in merge request !1906 (merged)

mentioned in commit 214aa505

merged