userportal, webadmin: fixed findbugs error in HelpTagJsonServlet

Fixed findbugs error in HelpTagJsonServlet by wrapping the FileInputStream
open in the try (new Java 7 syntax)

Change-Id: Iafa02467e3b54af6254481e16fdcd26c7feab89d
Signed-off-by: Greg Sheremeta <gshereme@redhat.com>