Fix nullable value in TKafkaRecord

[FloatingCrowbar]

Changelog entry

Fix TKafkaRecord

Changelog category

• Not for changelog (changelog entry is not required)

Description for reviewers

...

[github-actions]

🟢 2025-04-23 12:13:38 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-04-23 12:15:33 UTC Pre-commit check linux-x86_64-release-asan for 58c71ee has started.
⚪ 2025-04-23 12:16:03 UTC Artifacts will be uploaded here
⚪ 2025-04-23 12:19:30 UTC ya make is running...
🟡 2025-04-23 13:41:03 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet Going to retry failed tests...

Details

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
14297	14107	0	118	47	25

⚪ 2025-04-23 13:42:20 UTC ya make is running... (failed tests rerun, try 2)
🟡 2025-04-23 13:55:52 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet Going to retry failed tests...

Details

Test history | Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
226 (only retried tests)	157	0	37	10	22

⚪ 2025-04-23 13:56:01 UTC ya make is running... (failed tests rerun, try 3)
🟡 2025-04-23 14:08:48 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet

Test history | Ya make output | Test bloat | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
92 (only retried tests)	32	0	35	4	21

🟢 2025-04-23 14:08:55 UTC Build successful.
🟢 2025-04-23 14:09:25 UTC ydbd size 3.8 GiB changed* by +14.3 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 9731c04	merge: 58c71ee	diff	diff %
ydbd size	4 133 758 840 Bytes	4 133 773 496 Bytes	+14.3 KiB	+0.000%
ydbd stripped size	1 431 217 464 Bytes	1 431 222 904 Bytes	+5.3 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]

⚪ 2025-04-23 12:21:41 UTC Pre-commit check linux-x86_64-relwithdebinfo for 58c71ee has started.
⚪ 2025-04-23 12:22:09 UTC Artifacts will be uploaded here
⚪ 2025-04-23 12:25:30 UTC ya make is running...
🟡 2025-04-23 13:37:54 UTC Some tests failed, follow the links below. Going to retry failed tests...

Details

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
22062	20681	0	3	1269	109

⚪ 2025-04-23 13:39:46 UTC ya make is running... (failed tests rerun, try 2)
🟡 2025-04-23 13:52:45 UTC Some tests failed, follow the links below. Going to retry failed tests...

Details

Test history | Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
166 (only retried tests)	69	0	1	0	96

⚪ 2025-04-23 13:52:55 UTC ya make is running... (failed tests rerun, try 3)
🟢 2025-04-23 14:05:05 UTC Tests successful.

Test history | Ya make output | Test bloat | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
128 (only retried tests)	36	0	0	0	92

🟢 2025-04-23 14:05:14 UTC Build successful.
🟢 2025-04-23 14:05:38 UTC ydbd size 2.2 GiB changed* by +6.6 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 8a1e54f	merge: 58c71ee	diff	diff %
ydbd size	2 353 140 576 Bytes	2 353 147 296 Bytes	+6.6 KiB	+0.000%
ydbd stripped size	493 968 736 Bytes	493 969 248 Bytes	+512 Bytes	+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}