Fix canUploadKeysWithPasswordOnly for MSC3967

Being able to upload keys without any auth works too, so return true.
Otherwise we have to go the same route via the InteractiveAuthDialog
which is way more complex.

src/CreateCrossSigning.ts

@@ -23,11 +23,11 @@ import InteractiveAuthDialog from "./components/views/dialogs/InteractiveAuthDia
 async function canUploadKeysWithPasswordOnly(cli: MatrixClient): Promise<boolean> {
     try {
         await cli.uploadDeviceSigningKeys(undefined, {} as CrossSigningKeys);
-        // We should never get here: the server should always require
-        // UI auth to upload device signing keys. If we do, we upload
-        // no keys which would be a no-op.
+        // If we get here, it's because the server is allowing us to upload keys without
+        // auth the first time due to MSC3967. Therefore, yes, we can upload keys
+        // (with or without password, technically, but that's fine).
         logger.log("uploadDeviceSigningKeys unexpectedly succeeded without UI auth!");
-        return false;
+        return true;
     } catch (error) {
         if (!(error instanceof MatrixError) || !error.data || !error.data.flows) {
             logger.log("uploadDeviceSigningKeys advertised no flows!");