Fix big where encoded responses with a Content-Length where having their Content-Length measured against the encoded body, not decoded

Author: benjih

core/import.go

@@ -159,7 +159,8 @@ func (hf *Hoverfly) importRequestResponsePairViews(pairViews []v2.RequestMatcher
 
 			if len(pairView.Response.Headers["Content-Length"]) > 0 {
 				contentLength, err := strconv.Atoi(pairView.Response.Headers["Content-Length"][0])
-				if err == nil && contentLength != len(pairView.Response.Body) {
+				response := models.NewResponseDetailsFromResponse(pairView.Response)
+				if err == nil && contentLength != len(response.Body) {
 					importResult.AddContentLengthMismatchWarning(i)
 				}
 			}

core/import_test.go

@@ -726,7 +726,7 @@ func TestImportImportRequestResponsePairs_ReturnsWarningsContentLengthAndTransfe
 			Body:        base64String("hello_world"),
 			EncodedBody: true,
 			Headers: map[string][]string{
-				"Content-Length":    []string{"16"},
+				"Content-Length":    []string{"11"},
 				"Transfer-Encoding": []string{"chunked"},
 			},
 		},