Fix not null condition was is null

[MBkkt]

Changelog category

• Not for changelog (changelog entry is not required)

Description for reviewers

Fix bug introducent in recent PR

[github-actions]

⚪ 2025-02-16 14:44:24 UTC Pre-commit check linux-x86_64-relwithdebinfo for 9f4158d has started.
⚪ 2025-02-16 14:50:37 UTC Artifacts will be uploaded here
⚪ 2025-02-16 14:53:45 UTC ya make is running...
🟡 2025-02-16 15:56:00 UTC Some tests failed, follow the links below. Going to retry failed tests...

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
26345	23749	0	3	2461	132

⚪ 2025-02-16 15:59:10 UTC ya make is running... (failed tests rerun, try 2)
🟢 2025-02-16 16:27:00 UTC Tests successful.

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

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
209 (only retried tests)	80	0	0	0	129

🟢 2025-02-16 16:27:07 UTC Build successful.
🟢 2025-02-16 16:27:27 UTC ydbd size 2.1 GiB changed* by 0 Bytes, which is <= 0 Bytes vs main: OK

ydbd size dash	main: f6c191d	merge: 9f4158d	diff	diff %
ydbd size	2 235 932 952 Bytes	2 235 932 952 Bytes	0 Bytes	0.000%
ydbd stripped size	473 766 104 Bytes	473 766 104 Bytes	0 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}

[github-actions]

⚪ 2025-02-16 14:44:29 UTC Pre-commit check linux-x86_64-release-asan for 9f4158d has started.
⚪ 2025-02-16 14:44:41 UTC Artifacts will be uploaded here
⚪ 2025-02-16 14:47:32 UTC ya make is running...
🟡 2025-02-16 16:01:49 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet Going to retry failed tests...

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
12177	12062	0	56	22	37

⚪ 2025-02-16 16:03:15 UTC ya make is running... (failed tests rerun, try 2)
🟢 2025-02-16 16:21:10 UTC Tests successful.

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

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
171 (only retried tests)	136	0	0	4	31

🟢 2025-02-16 16:21:18 UTC Build successful.
🟢 2025-02-16 16:21:45 UTC ydbd size 3.6 GiB changed* by -96 Bytes, which is <= 0 Bytes vs main: OK

ydbd size dash	main: f6c191d	merge: 9f4158d	diff	diff %
ydbd size	3 889 415 240 Bytes	3 889 415 144 Bytes	-96 Bytes	-0.000%
ydbd stripped size	1 361 429 552 Bytes	1 361 429 488 Bytes	-64 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}