This story is not believable at all.
Here are another couple sources:
http://www.nbcnews.com/politics/2016-election/gop-senator-bob-bennett-apologized-muslims-trump-while-deathbed-n576566
http://www.washingtontimes.com/news/2016/may/18/bob-bennett-apologized-muslims-donald-trump-final-/