fix registration add phone number not working (#2876)
fix registration add phone number not working (#2876)

Co-authored-by: Michael Weimann <5059b5df59e67be29faa89536427a574a4318434@matrix.org>
matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk