Bridge returned HTTP 500 Internal Server Error: Bridging request already sent

### Description

I am trying to bridge/plumb a Matrix room to a channel on Libera.Chat using the integrations manager. I could send a bridging request but it did not reach me on IRC end. (Potentially because I am connected to the Libera.Chat IRC network via the new and unstable "global bridge" that is the libera.chat Matrix-homeserver.) When I try to resend the request half a day later, I get the message `Bridge returned HTTP 500 Internal Server Error: Bridging request already sent …`.

### Steps to reproduce

- Request an IRC integration via Element's integration manager.
- Do not respond to it on IRC side.
- Attempt to re-request it some time later.

### Expected behavior

If the bridging request isn't answered by the designated IRC channel operator, one should be able to resend it after some time.

### Version information

- **Platform**: Element Desktop
- **OS**: Arch Linux (Linux 5.12.6)
- **Version**: 1.7.29