Menu block: "Notice: Undefined index"

## Ready state: Yes
Suppress php notice about undefined index on menu_block, this patch has been applied to module dev 
release already.
This patch relates to: https://drupal.org/node/1885576

## Deployment Instructions
1. Apply `menu_block-7.x-2.3_0.patch` case seeing the php notice
2. Only uses `menu_block-7.x-2.3-plugin_0.patch` case 1 fails.