Update wisp.gleam, fix double-import

[matt-savvy]

Fixes a bug that was introduced by 23d1477, maybe a bug in wisp fix?

Response is being doubly imported and aliased.

$ gleam --version
gleam 0.32.1

$ gleam build
  Compiling wisp
error: Duplicate type definition
   ┌─ ../dev/wisp/src/wisp.gleam:12:3
   │
12 │   type Response as HttpResponse, Response as HttpResponse,
   │   ^^^^^^^^^^^^^                  ^^^^^^^^ Redefined here
   │   │
   │   First defined here

The type `HttpResponse` has been defined multiple times.
Names in a Gleam module must be unique so one will need to be renamed.

[matt-savvy]

Actually, this turns out to be correct