Dashboard Banner Fix.

[YegorSan]

@vbaranov
Hello Victor. I've re-created this PR and closing #2673 with the same update, but with unresolved merge conflict. Finally, I've the resolved merge conflicts in my local repo, and will never push anything to master anymore:

:

Motivation

Bug with dashboard banner must be resolved.

Changelog

Bug Fixes

Fixed jumping bug with dashboard banner on main Blockscout page.

Checklist for your PR

• I added an entry to CHANGELOG.md with this PR
• If I added new functionality, I added tests covering it.
• If I fixed a bug, I added a regression test to prevent the bug from silently reappearing again.
• I checked whether I should update the docs and did so if necessary
• If I added/changed/removed ENV var, I should update the list of env vars in https://github.com/poanetwork/blockscout/blob/master/docs/env-variables.md to reflect changes in the table here https://poanetwork.github.io/blockscout/#/env-variables?id=blockscout-env-variables. I've set master in the Version column.
• If I add new indices into DB, I checked, that they don't redundant with PGHero or other tools

[vbaranov]

@YegorSan please add CHANGELOG entry

[YegorSan]

@vbaranov Hello. Added new changelog entry.