[Bug] Kittygram redirects include an extra slash (`/`)

[irelephanttt]

I run https://kittygram.irelephant.net. I was looking through the logs a bit ago and noticed that a lot of people were going to routes like //p/DNJOyzyhYuV/ (example: https://kittygram.irelephant.net//DNJOyzyhYuV/) instead of /p/DNJOyzyhYuV (example: https://kittygram.irelephant.net/p/DNJOyzyhYuV/).
I tested libredirect, and it redirected me to a malformed path with an extra slash.
This means a lot of users are getting 404s after getting redirected.