Bug 454239 - RAP: Improve DeviceDispatcherServlet robustness
https://bugs.eclipse.org/bugs/show_bug.cgi?id=454239

Improved "root" request recognition for dispatching by checking null and
empty path info (which can occurr as described in the javadoc of
"HttpServletRequest.getPathInfo")


Change-Id: Ib9ffaf1b2aba13bbb1c86e2f93a68877d60da461
Reviewed-on: https://git.eclipse.org/r/37659
Tested-by: Hudson CI
Reviewed-by: Claudio Guglielmo <claudio.guglielmo@bsiag.com>