Restored the logo on the portal (picture with transparent background)

git-svn-id: http://svn.code.sf.net/p/itop/code/trunk@2827 a333f486-631f-4898-b8df-5754b55c2be0

portal/portal.css

@@ -42,7 +42,7 @@ div#portal #banner {
     max-width: 90%;
     min-width: 960px;
     position: relative;
-    margin-bottom: 3em;
+    margin-bottom: 1em;
 }
 
 div#portal #logo {