Fix events url location

xsl/events.xsl

@@ -18,7 +18,7 @@
       <tr>
         <td class="eventdate"><xsl:value-of select="@date" /></td>
         <td rowspan="2" valign="top" class="eventitem">
-          <a href="{translate(concat('/events/', @room, '-', @date, '-', @time), ' ', '_')}">
+          <a href="{translate(concat($g_pre, 'events/', @room, '-', @date, '-', @time), ' ', '_')}">
             <xsl:value-of select="@title" />
           </a>.
           <xsl:value-of select="short" />