fix: accept bare Pi-hole IPv4 addresses

internal/web/templates/layout.html

@@ -6,8 +6,8 @@
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <meta name="color-scheme" content="light">
   <title>{{.Title}} · DNS Control</title>
-  <link rel="stylesheet" href="/static/styles.css?v=features-14">
-  <script src="/static/app.js?v=features-14" defer></script>
+  <link rel="stylesheet" href="/static/styles.css?v=features-15">
+  <script src="/static/app.js?v=features-15" defer></script>
 </head>
 <body class="page-{{.Page}}">
   <a class="skip-link" href="#main">Zum Inhalt springen</a>