Added alert() message when Certificate Password is too short.

src/js/app.js

@@ -104,6 +104,7 @@ document.addEventListener("DOMContentLoaded", function () {
                 let password = passwordInput.value;
 
                 if (password === "" || password.length < 8) {
+		    alert("The password must be at least 8 characters long.");
                     return false;
                 }
 
@@ -282,4 +283,4 @@ document.addEventListener("DOMContentLoaded", function () {
             return false;
         }
     });
-});
+});