add new frankfurt region to list in webapp

But commented out for now, because:

The authorization mechanism you have provided is not supported. Please use
AWS4-HMAC-SHA256
Merge branch 'master' of ssh://git-annex.branchable.com
rename isIA to configIA

Already done on s3-aws branch, so reduce divergence.
Merge branch 'master' of ssh://git-annex.branchable.com