Check for liveliness on submission when the server was previously dead
Check for liveliness on submission when the server was previously dead

Fixes https://github.com/vector-im/riot-web/issues/10017

Specifically the `return` at the end of the diff fixes the problem, but it seems worthwhile to check for liveliness when we know the server has been dead in previous attempts.
matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk