[FIX] ODataModel: Unnecessary question mark in batch URLs

When no URL parameters are defined by the application, all request URLs
for batch requests had an unnecessary question mark appended.

CSS: 0120031469 0000742176 2014
Change-Id: I9f0f9c035d4ad3d9eb586ec29df6c81112ba9e80
Merge "[FIX] ODataModel: Unnecessary question mark in batch URLs"