Make dropdown style on repository page consistent

app/assets/stylesheets/pages/tree.scss

@@ -202,6 +202,28 @@
       }
     }
   }
+
+  // TODO: fallback to global style
+  .dropdown-menu:not(.dropdown-menu-selectable) {
+    li {
+      padding: 0 1px;
+
+      &.dropdown-header {
+        padding: 8px 16px;
+      }
+
+      a {
+        border-radius: 0;
+        padding: 8px 16px;
+
+        &:hover,
+        &:active,
+        &:focus {
+          background-color: $gray-darker;
+        }
+      }
+    }
+  }
 }
 .blob-commit-info {