Use time zone from host

[casperklein]

Description

It's probably intended behaviour, that the container uses the same timezone as the host. If nothing is configured, UTC is used.
Without a proper configured timezone, e.g. log files will have time offset.

Inspired by #1849

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Improvement (non-breaking change that does improve existing functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

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 (README.md or ENVIRONMENT.md or the Wiki)
• If necessary 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