fix: initialize echo instance with LegacyIPExtractor

echo.go

@@ -185,7 +185,6 @@ const (
 	// RouteAny is a special method type that matches any HTTP method in request. Any has lower
 	// priority that other methods that have been registered with Router to that path.
 	RouteAny = "echo_route_any"
-
 )
 
 // Headers
@@ -396,6 +395,7 @@ func New() *Echo {
 		Binder:             &DefaultBinder{},
 		JSONSerializer:     &DefaultJSONSerializer{},
 		formParseMaxMemory: defaultMemory,
+		IPExtractor:        LegacyIPExtractor(),
 	}
 
 	e.serveHTTPFunc = e.serveHTTP

echo_test.go

@@ -82,6 +82,12 @@ func TestNewWithConfig(t *testing.T) {
 	assert.Equal(t, `Hello, World!`, rec.Body.String())
 }
 
+func TestNew(t *testing.T) {
+	e := New()
+
+	assert.IsType(t, e.IPExtractor, LegacyIPExtractor())
+}
+
 func TestNewDefaultFS(t *testing.T) {
 	tempDir := t.TempDir()
 	filename := filepath.Join(tempDir, "file.txt")