Revert "feat: added error handler"

This reverts commit acc2a94.

This does not work with AbortErrors. It yields `undefined`. No clue
what's the point of this

src/HttpClient.js

@@ -75,9 +75,6 @@ function request(url, {json, method, params, ...customConfig} = {}) {
                 const errorMessage = `${response.status} ${response.statusText}: ${response.headers.get('x-viur-error')}`
                 return Promise.reject(new HTTPError(response.status, response.statusText, errorMessage, response))
             }
-        }).catch((error) => {
-            const errorMessage = `${error.statusCode} ${error.statusText}: ${error.response.headers.get('x-viur-error')}`
-            return Promise.reject(new HTTPError(error.statusCode, error.statusText, errorMessage, error))
         })
 }