Currently, there is no way to get the client IP address from a web request when using the proxy service. The account-creation-assistance project needs access to the client IP for abuse prevention, and also needs SSL for security, and there's currently no way to get both.
Version: unspecified
Severity: normal
This is a reasonable request. For privacy purposes we'd prefer to enable it selectively rather than for all proxies, so there will be a bit of development involved.
Simon, this should be resolved now, via
https://gerrit.wikimedia.org/r/#/c/105509/
please verify that you're getting what you need and close this bug.