Fix the bug that display "0" on an unvoted requirement in OpenGameView.

Reported-by: hlong290494
Signed-off by: Long Nguyen Duc Hoang <lhnguyenduc@wpi.edu>
Merge pull request #417 from hlong290494/ZeroUnvotedFix

Fix the bug that display "0" on an unvoted requirement in OpenGameView.