Describe the bug
Upgrade to cats latest version hit a breaking change. It adds a default "/"

Version 13.2.0 works fine.
Version 13.4.3 as the problem.

To Reproduce

Swagger v2.0:

paths:
  /run:

Using functional fuzzer:

/run:
  getRun:
  ...

In Test1.json result: Notice the double "/"
"url": "http://localhost:3000//run/myValue"

So to make it work, I have to remove the header "/" to each path which is not swagger v2.0 standard..

e.g.

paths:
  run:

Note the issue happens regardless of the basePath settings or not.