Fix href link for Add Relation button

Author: thiagogq

relations.html

@@ -57,7 +57,7 @@
     <div id="content">
       <div class="title-div">
         <span>Relations</span> 
-        <a class="button" href="/relation-edit.html">Add Relation</a>
+        <a class="button" href="relation-edit.html">Add Relation</a>
       </div>
       <div class="details-header">
         <details class="extrainfo">