Merge pull request #1927 from Evolena/master

Fix thumbnail macro when no caption parameter is provided

core/wiki/macros/thumbnails.tid

@@ -9,7 +9,8 @@ tags: $:/tags/Macro
 $icon$
 </div><div class="tc-thumbnail-caption">
 $caption$
-</div></div></$link>
+</div>
+</div></$link>
 \end
 
 \define thumbnail-right(link,icon,color,background-color,image,caption,width:"280",height:"157")