Blobs balancer: fix unhadled event in case of chunk read timeout

[robdrynkin]

• Not for changelog (changelog entry is not required)

[github-actions]

⚪ 2024-10-02 16:30:44 UTC Pre-commit check linux-x86_64-relwithdebinfo for 65e5d24 has started.
⚪ 2024-10-02 16:31:19 UTC Artifacts will be uploaded here
⚪ 2024-10-02 16:34:42 UTC ya make is running...
🟡 2024-10-02 17:22:56 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?
15433	13959	0	1	1377	96

⚪ 2024-10-02 17:24:13 UTC ya make is running... (failed tests rerun, try 2)
🟢 2024-10-02 17:35:27 UTC Tests successful.

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

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
96 (only retried tests)	5	0	0	0	91

🟢 2024-10-02 17:35:33 UTC Build successful.
🟡 2024-10-02 17:35:51 UTC ydbd size 2.8 GiB changed* by +122.2 KiB, which is >= 100.0 KiB vs main: Warning

ydbd size dash	main: 8030e8b	merge: 65e5d24	diff	diff %
ydbd size	3 001 455 544 Bytes	3 001 580 688 Bytes	+122.2 KiB	+0.004%
ydbd stripped size	477 330 168 Bytes	477 351 128 Bytes	+20.5 KiB	+0.004%

^{*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]

⚪ 2024-10-02 16:31:55 UTC Pre-commit check linux-x86_64-release-asan for 65e5d24 has started.
⚪ 2024-10-02 16:32:06 UTC Artifacts will be uploaded here
⚪ 2024-10-02 16:35:00 UTC ya make is running...
🟡 2024-10-02 18:20:34 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?
10691	10502	0	51	32	106

🟢 2024-10-02 18:21:28 UTC Build successful.
🟢 2024-10-02 18:22:04 UTC ydbd size 5.7 GiB changed* by -160 Bytes, which is <= 0 Bytes vs main: OK

ydbd size dash	main: 100fc57	merge: 65e5d24	diff	diff %
ydbd size	6 085 664 824 Bytes	6 085 664 664 Bytes	-160 Bytes	-0.000%
ydbd stripped size	1 520 483 120 Bytes	1 520 482 864 Bytes	-256 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}