clicking jsdoc-summary-toggle causes nodeType = null in query

[lbod]

a tracker for:

• load for example http://localhost:3000/api/?qs=1.9/dojo/NodeList
• click on any of the jsdoc-summary-toggle arrows on the summary headings

Uncaught TypeError: Cannot read property 'nodeType' of null

[lbod]

Actually this is the same on the production site, so it's not a regression, minor but will look to fix