feat(assets): make URLs for favicons relative (#1343)

assets/ico/browserconfig.xml

@@ -2,7 +2,7 @@
 <browserconfig>
     <msapplication>
         <tile>
-            <square150x150logo src="/ico/mstile-150x150.png"/>
+            <square150x150logo src="ico/mstile-150x150.png"/>
             <TileColor>#2d89ef</TileColor>
         </tile>
     </msapplication>

assets/ico/manifest.json

@@ -2,12 +2,12 @@
     "name": "Portainer",
     "icons": [
         {
-            "src": "/ico/android-chrome-192x192.png",
+            "src": "ico/android-chrome-192x192.png",
             "sizes": "192x192",
             "type": "image/png"
         },
         {
-            "src": "/ico/android-chrome-256x256.png",
+            "src": "ico/android-chrome-256x256.png",
             "sizes": "256x256",
             "type": "image/png"
         }

index.html

@@ -24,13 +24,13 @@
   <!-- endbuild -->
 
   <!-- Fav and touch icons -->
-  <link rel="apple-touch-icon" sizes="180x180" href="/ico/apple-touch-icon.png">
-  <link rel="icon" type="image/png" sizes="32x32" href="/ico/favicon-32x32.png">
-  <link rel="icon" type="image/png" sizes="16x16" href="/ico/favicon-16x16.png">
-  <link rel="manifest" href="/ico/manifest.json">
-  <link rel="mask-icon" href="/ico/safari-pinned-tab.svg" color="#5bbad5">
-  <link rel="shortcut icon" href="/ico/favicon.ico">
-  <meta name="msapplication-config" content="/ico/browserconfig.xml">
+  <link rel="apple-touch-icon" sizes="180x180" href="ico/apple-touch-icon.png">
+  <link rel="icon" type="image/png" sizes="32x32" href="ico/favicon-32x32.png">
+  <link rel="icon" type="image/png" sizes="16x16" href="ico/favicon-16x16.png">
+  <link rel="manifest" href="ico/manifest.json">
+  <link rel="mask-icon" href="ico/safari-pinned-tab.svg" color="#5bbad5">
+  <link rel="shortcut icon" href="ico/favicon.ico">
+  <meta name="msapplication-config" content="ico/browserconfig.xml">
   <meta name="theme-color" content="#ffffff">
 </head>