Fix oversided logs entry in downloader

[georgeee]

Downloader prints oversized logs. Oversized logs are discouraged and we should strive to fix all of them

The issue might be solely in logging, but it's also worth to see if the memory might be leaking because of ever-growing state (could it be the indirect cause of the extra-large log entry)?

Steps to Reproduce

Appears on some BPs.

Expected Result

no oversized logs

Actual Result

https://drive.google.com/file/d/1V9zIh2BPrv3v9FimLlPbQ4Lrv7vBQrhc/view?usp=sharing

How frequently do you see this issue?

Frequently

What is the impact of this issue on your ability to run a node?

Low