Remove Google Analytic, fixes #1250

[pgporada]

[pgporada]

Do we need any of the Google stuff in the CSP? https://developers.google.com/tag-manager/web/csp

[tdelmas]

You shouldn't need https://www.googleadservices.com, https://www.googletagmanager.com and https://googleads.g.doubleclick.net.

script-src 'unsafe-eval' 'unsafe-inline' 'self' data: may be partially needed for the stats page.

[jprenken]

I made some further changes and am happy, but I think this needs full testing of Donorbox, and PMA review of the privacy policy update.