Tests: prevent exception

Avoid error when running make qunit
Exception thrown by ext.mobilefrontend.tests:
'undefined' is not an object (evaluating 'el.ontouchstart=cancelBubble')
TypeError: 'undefined' is not an object (evaluating 'el.ontouchstart=cancelBubble')

Change-Id: If579ec5d1add71d4c18fd4555d3b2aa2b8d1dd87
Merge "Tests: prevent exception"