babeld: fix interface_recalculate function, initializing ipv4 field

[Shbinging]

In interface_recalculate function, one should initialize babel_ifp->ipv4 field. CLOSES https://github.com/FRRouting/frr/issues/18492

[riw777]

looks like the ci failure is related and needs to be fixed.

Address Sanitizer Error detected in babel_topo1.test_babel_topo1/r1.asan.babeld.1871
Address Sanitizer Error detected in babel_topo1.test_babel_topo1/r3.asan.babeld.2105
Address Sanitizer Leak triggered - Test failed```

[github-actions[bot]]

This pull request has conflicts, please resolve those before we can evaluate the pull request.

[riw777]

@Mergifyio rebase

[mergify[bot]]

rebase

☑️ Nothing to do, the required conditions are not met

• [ ] -conflict [📌 rebase requirement]
• [X] -closed [📌 rebase requirement]
• [X] queue-position = -1 [📌 rebase requirement]
• [X] any of:
  • [X] #commits-behind > 0 [📌 rebase requirement]
  • [ ] #commits > 1 [📌 rebase requirement]
  • [ ] -linear-history [📌 rebase requirement]