🩹 Fix: ErrorHandler incorrect selection due map iteration

Author: duhnnie

app.go

@@ -1041,8 +1041,9 @@ func (app *App) ErrorHandler(ctx *Ctx, err error) error {
 		mountedPrefixParts int
 	)
 
-	for prefix, subApp := range app.mountFields.appList {
-		if prefix != "" && strings.HasPrefix(ctx.path, prefix) {
+	for _, prefix := range app.mountFields.appListKeys {
+		subApp := app.mountFields.appList[prefix]
+		if prefix != "" && strings.HasPrefix(ctx.Path(), prefix) {
 			parts := len(strings.Split(prefix, "/"))
 			if mountedPrefixParts <= parts {
 				if subApp.configured.ErrorHandler != nil {