Enforce MPD setup during installation

[AlvinSchiller]

Following the report of #2306:

• The user option for MPD setup is removed. Instead the mpd.conf is always deployed, as Phoniebo is not functionally otherwise. The manual process to fix this is not straight forward and error prone.
• Multiple sample conf files existed in the repo. This was cleaned to only have one left used by the setup.

TODO:

• manual installation tests on device

[AlvinSchiller]

@s-martin
Additional change suggestion (already checked in but can be reverted):

• Currently the spotify installation defaults to "yes". As spotify is not working for some time now, without user changes, the default should be changed to "no", having the "classic" edition as default.

[coveralls]

Pull Request Test Coverage Report for Build 8452689755

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 78.435%

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Totals
Change from base Build 8416480811:	0.0%
Covered Lines:	451
Relevant Lines:	575

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💛 - Coveralls

[s-martin]

@s-martin
Additional change suggestion (already checked in but can be reverted):

• Currently the spotify installation defaults to "yes". As spotify is not working for some time now, without user changes, the default should be changed to "no", having the "classic" edition as default.

Yes!