Move text overflow to a to avoid false positives

Author: josevalim

assets/less/sidebar.less

@@ -230,7 +230,6 @@
       line-height: 27px;
       white-space: nowrap;
       overflow: hidden;
-      text-overflow: ellipsis;
 
       &.open > ul {
         display: block;
@@ -253,6 +252,10 @@
         color: @groupGray;
       }
 
+      a.expand {
+        text-overflow: ellipsis;
+      }
+
       a.expand span {
         color: @lightestGray;
         opacity: 0;