make link to dataresource relative

Author: hagbeck

src/main/resources/views/index.ftl.html

@@ -7,7 +7,7 @@ <h2>Available datasets</h2>
   <dl class="datasets">
       <#if datasources??>
     <#list datasources?keys as datasourceName>
-        <dt><a href="/${datasourceName}">${datasources[datasourceName].getTitle() }</a></dt>
+        <dt><a href="${datasourceName}">${datasources[datasourceName].getTitle() }</a></dt>
         <dd>${ datasources[datasourceName].getDescription()!"" }</dd>
     </#list>
     </#if>