fix for #1: Building a project with one axis does not show any labels

Now works for a project with one axis.
[matrixwithoneaxis](!https://f.cloud.github.com/assets/3115961/1245652/b2eaf822-2aa1-11e3-9e23-4cf0298619e9.png)

For I used a jelly taglib /lib/hudson/project, "Configurations" is displayed for single axis.

BTW, links in "Select:" line does not work.
This feature seems imported from MatrixReloaded plugin, but I think this is not so useful for this plugin even if it works.
How about removing it?