KIKIMR-21693: Fix null dereference in node broker

[pixcc]

Changelog entry

Fix null pointer dereference during node registration in Node Broker.

Changelog category

• Bugfix

[github-actions]

⚪ 2024-07-10 10:14:26 UTC Pre-commit check for b928ae8 has started.
⚪ 2024-07-10 10:17:20 UTC Build linux-x86_64-relwithdebinfo is running...
🟢 2024-07-10 10:54:03 UTC Build successful.
⚪ 2024-07-10 10:54:12 UTC Tests are running...
🔴 2024-07-10 12:10:07 UTC Some tests failed, follow the links below.

Test history | Test log

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
14094	12764	0	1	1308	21

🟢 2024-07-10 12:10:46 UTC ydbd size 8.1 GiB changed* by +27.3 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 483e9ee	merge: b928ae8	diff	diff %
ydbd size	8 721 407 872 Bytes	8 721 435 792 Bytes	+27.3 KiB	+0.000%
ydbd stripped size	475 018 016 Bytes	475 019 872 Bytes	+1.8 KiB	+0.000%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}

[github-actions]

⚪ 2024-07-10 10:15:38 UTC Pre-commit check for b928ae8 has started.
⚪ 2024-07-10 10:18:03 UTC Build linux-x86_64-release-clang14 is running...
🟢 2024-07-10 10:22:58 UTC Build successful.

[github-actions]

⚪ 2024-07-10 10:21:26 UTC Pre-commit check for b928ae8 has started.
⚪ 2024-07-10 10:23:52 UTC Build linux-x86_64-release-asan is running...
🟢 2024-07-10 10:47:34 UTC Build successful.
⚪ 2024-07-10 10:47:48 UTC Tests are running...
🔴 2024-07-10 12:44:11 UTC Some tests failed, follow the links below.

Test history | Test log

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
9819	9239	0	81	323	176

🟢 2024-07-10 12:45:05 UTC ydbd size 5.2 GiB changed* by +22.4 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 483e9ee	merge: b928ae8	diff	diff %
ydbd size	5 611 370 560 Bytes	5 611 393 472 Bytes	+22.4 KiB	+0.000%
ydbd stripped size	1 206 696 760 Bytes	1 206 700 760 Bytes	+3.9 KiB	+0.000%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}