bgpd: When receiving a label, store it

[donaldsharp]

No description provided.

[ton31337]

@Mergifyio backport stable/9.1 stable/9.0

[mergify]

backport stable/9.1 stable/9.0

✅ Backports have been created

• #15044 bgpd: When receiving a label, store it (backport #15002) has been created for branch stable/9.1
• #15045 bgpd: When receiving a label, store it (backport #15002) has been created for branch stable/9.0

[donaldsharp]

For a bit of background on what this is:

a) Trey contacted me yesterday asking for some help on a couple months old discussion in slack. Gave me a brief explanation of the problem.
b) I guessed on a fix. Frankly I'm not sure what this is going to do.
c) We've asked the people who were in the discussion to try this fix out.
d) Once it works or doesn't work for them, I may need to re-adjust. Dunno
e) I'm gonna have Trey help me write a much better commit message once we get (d) solved.
f) Then I'll remove the do not merge tag

[riw777]

looks good