message: Fix spurious extra devices on registration
  We send a parameter to prevent being immediately logged in after
  registration, but we regressed it from snake case to camelcase
  during the course of cross-signing dev.
  Fixes
diff: @@ -463,7 +463,7 @@ export default createReactClass({
  initial_device_display_name: this.props.defaultDeviceDisplayName,
  };
  if (auth) registerParams.auth = auth;
  - if (inhibitLogin !== undefined && inhibitLogin !== null) registerParams.inhibitLogin = inhibitLogin;
  + if (inhibitLogin !== undefined && inhibitLogin !== null) registerParams.inhibit_login = inhibitLogin;
  return this.state.matrixClient.registerRequest(registerParams);
  },
  