fixed issue with missing rewards crashing the app
Update UnityAdsRewardItem.m

changed these to just nil checks to avoid downstream crashes from not properly handling nil data.
Merge branch 'malfor-data-fix' of https://github.com/scopely/unity-ads into scopely-malfor-data-fix
Fail gracefully on invalid server-side zone configuration
Merge branch 'scopely-malfor-data-fix'