replace relative include of gethost.js with absolute one. This is needed as that file gets incuded on dynamically generated content which can be on different path levels (#1610)

Co-authored-by: CaCO3 <caco@ruinelli.ch>

sd-card/html/upload_script.html

@@ -30,8 +30,7 @@
     </td></tr>
 </table>
 
-<script type="text/javascript" src="./html/gethost.js">
-// Achtung dieses Script wird mit /fileserver aufgerufen, daher muss hier /html/gethost.js verwendet werden!    
+<script type="text/javascript" src="/fileserver/html/gethost.js"> 
 </script>            
 <script language="JavaScript">
 function setpath() {