webadmin: reduce autocompleter time in chrome

- The profiler in chrome was indicating that the autocompleter
  was taking significant amounts of time during login. This time
  was taken mostly loading the exception handlers. I modified
  the code to not throw exceptions during the time of day lookup.
  Running the profiler in FF didn't seem to be affected by this.

Change-Id: I3f9f0e26274caef5745d2adae9d573498ca6cf4c
Signed-off-by: Alexander Wels <awels@redhat.com>