fix(config): increase default disk read limit for basebackup creation

[Endevir]

Description

This increases backup creation disk bandwidth limit for WAL-G from 7.5MB/s to 300 MB/s, which is fast enough to backup 100GB database in under 6 minutes, but not too high for modern SSD devices with bandwidth 1+GB/s.

Fixes #54

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• Unit tests
• Integration tests
• Manual tests

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules