Update proposals/2229-rebind-existing-3pid.md
Update proposals/2229-rebind-existing-3pid.md

Co-Authored-By: Travis Ralston <f36f6a6abc4b55589c96c71fceedf83e596b8f33@gmail.com>
matrix-org/matrix-doc,matrix-org/matrix-doc,matrix-org/matrix-doc,matrix-org/matrix-doc