Use JSONP for gender query to avoid cross-domain issues

Querying the uploader's gender defaults to CORS, which is disallowed
for non-WMF sites and spams the javascript console with XHR errors.
JSONP works in such cases, and has no disadvantages I can think of.

Change-Id: I9b13210e03059a46407f119045540665c48585ad
Merge "Use JSONP for gender query to avoid cross-domain issues"