[Openid-specs-ab] Issue #1119: place_of_birth -> birthplace (openid/connect)

[Travis Spencer]

New issue 1119: place_of_birth -> birthplace
https://bitbucket.org/openid/connect/issues/1119/place_of_birth-birthplace

Travis Spencer:

[Section 3.1 of the identity assurance draft spec](https://openid.net/specs/openid-connect-4-identity-assurance-1_0-07.html#rfc.section.3.1) defines a new claim called `place_of_birth`. This would be more natural if renamed to birthplace \(one word\).