[Minor] Remove leftover CSS rule set

interface/css/rspamd.css

@@ -39,17 +39,6 @@ textarea {
 .navbar-brand > img {
     height: 50px;
 }
-.disconnect {
-    margin: 9px 0 0;
-    padding-bottom: 5px;
-    font-size: 11px;
-    color: #777;
-    -moz-text-shadow: 0 1px 0 #fff;
-    -webkit-text-shadow: 0 1px 0 #fff;
-    -o-text-shadow: 0 1px 0 #fff;
-    -ms-text-shadow: 0 1px 0 #fff;
-    text-shadow: 0 1px 0 #fff;
-}
 .chart-content {
     text-align: center;
 }