Fix lighttpd MIME related error.

[RamSet]

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What does this PR aim to accomplish?:
Fixed issue related to lighttpd not starting/failing during install due to deprecated parameter in the config (migrated from older versions).

How does this PR accomplish the above?:
Commented out the old perl mime file path and hard coded generic MIME definitions within the config.

What documentation changes (if any) are needed to support this PR?:
None

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[pralor-bot]

This pull request has been mentioned on Pi-hole Userspace. There might be relevant details there:

https://discourse.pi-hole.net/t/getting-ready-for-buster/21001/19

[dschaper]

Do we want this to go to development or should this be a point release branch to get out?

[AzureMarker]

We can put it in a hotfix release. @RamSet, cherrypick your commits onto a new branch based off of master, and then make a PR against master.

[dschaper]

Can he just rebase his branch off master?

[AzureMarker]

Yes, that is functionally the same.

[dschaper]

See #2816