Change port for local registry (#906)

In one of the test we want a failure due to a 500 error returned by a
not existing local registry, the fake server address is set to localhost:5000
In a typical local env is quite likely to have a local registry running
and the default address usually is localhost:5000 and that will make the
test to return a 4xx error and not the expected 500 error, this change
just set a not standard port for the fake local registry to reduce the
chances to clash with an existing running one.

api/server/runner_test.go

@@ -327,7 +327,7 @@ func TestRouteRunnerExecution(t *testing.T) {
 	rHdr := map[string][]string{"X-Function": {"Test"}}
 	rImg := "fnproject/fn-test-utils"
 	rImgBs1 := "fnproject/imagethatdoesnotexist"
-	rImgBs2 := "localhost:5000/fnproject/imagethatdoesnotexist"
+	rImgBs2 := "localhost:5050/fnproject/imagethatdoesnotexist"
 
 	app := &models.App{Name: "myapp"}
 	app.SetDefaults()