YMQ: drop empty MD5* fields from JSON responses

[qyryq]

No description provided.

[github-actions]

⚪ 2024-10-04 09:03:57 UTC Pre-commit check linux-x86_64-relwithdebinfo for e43d04b has started.
⚪ 2024-10-04 09:04:09 UTC Artifacts will be uploaded here
⚪ 2024-10-04 09:07:26 UTC ya make is running...
🟡 2024-10-04 10:13:49 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?
79794	65866	0	5	13825	98

⚪ 2024-10-04 10:21:20 UTC ya make is running... (failed tests rerun, try 2)
🟢 2024-10-04 10:33:09 UTC Tests successful.

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

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
102 (only retried tests)	9	0	0	1	92

🟢 2024-10-04 10:33:17 UTC Build successful.
🟢 2024-10-04 10:33:35 UTC ydbd size 2.8 GiB changed* by 0 Bytes, which is <= 0 Bytes vs main: OK

ydbd size dash	main: 3ed2931	merge: e43d04b	diff	diff %
ydbd size	3 001 162 920 Bytes	3 001 162 920 Bytes	0 Bytes	0.000%
ydbd stripped size	477 259 512 Bytes	477 259 512 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]

⚪ 2024-10-04 09:04:12 UTC Pre-commit check linux-x86_64-release-asan for e43d04b has started.
⚪ 2024-10-04 09:04:24 UTC Artifacts will be uploaded here
⚪ 2024-10-04 09:07:38 UTC ya make is running...
🟡 2024-10-04 10:47:48 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
17019	16712	0	104	99	104

🟢 2024-10-04 10:49:14 UTC Build successful.
🟢 2024-10-04 10:49:46 UTC ydbd size 5.7 GiB changed* by -96 Bytes, which is <= 0 Bytes vs main: OK

ydbd size dash	main: 3ed2931	merge: e43d04b	diff	diff %
ydbd size	6 082 038 568 Bytes	6 082 038 472 Bytes	-96 Bytes	-0.000%
ydbd stripped size	1 519 792 240 Bytes	1 519 792 176 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}