Error when trying to set relative site logo URL in admin when using HTTP

[pdehaan]

I'm getting an error when specifying a relative site logo URL in the admin:

sitelogo URLs beginning with / must be served over https

I don't think this is correct. Currently I'm changing the settings in the admin over HTTP, but I shouldn't be seeing that error. We shouldn't be checking the protocol when saving the settings in the admin since it is irrelephant. The setting should only be verified when we pop the Persona login screen.

[shane-tomlinson]

@pdehaan - there were complaints about the suggested approach - site admins could specify an absolute path site logo over http and then lock themselves out of their own site while testing.