Looking at the validator, it’s:
s3_endpoint:
default: ""
regex: '^https?:\/\/.+[^\/]$'
so checking the value you put in shows it’s perfectly fine:
[1] pry(main)> 'https://b1v7.or.idrive2-51.com'.match /^https?:\/\/.+[^\/]$/
=> #<MatchData "https://b1v7.or.idrive2-51.com">
You evidently have something wrong in the field. As @pfaffman suggests, check for spaces.
If it still doesn’t work, does it work from the rails console?
I would expect this to fail:
[1] pry(main)> SiteSetting.s3_endpoint = 'gopher://b1v7.or.idrive2-51.com'
Discourse::InvalidParameters: s3_endpoint: Value doesn't match the required format.
from /home/michael/prog/Discourse/discourse/lib/site_settings/type_supervisor.rb:288:in `validate_value'
but this should work:
[1] pry(main)> SiteSetting.s3_endpoint = 'https://b1v7.or.idrive2-51.com'
=> "https://b1v7.or.idrive2-51.com"