Fix for crash on ios when selecting image
Fix for crash on ios when selecting image

Dictionary was being created with nil values. Added nil check and initialize with empty string instead
zoofei/react-native-my-image-crop-picker,zoofei/react-native-my-image-crop-picker,nico1510/react-native-image-crop-picker,ropc/react-native-image-crop-picker,nico1510/react-native-image-crop-picker,ivpusic/react-native-image-crop-picker,nico1510/react-native-image-crop-picker,ivpusic/react-native-image-crop-picker,zoofei/react-native-my-image-crop-picker,ivpusic/react-native-image-crop-picker,ropc/react-native-image-crop-picker,nico1510/react-native-image-crop-picker,ropc/react-native-image-crop-picker,ropc/react-native-image-crop-picker,zoofei/react-native-my-image-crop-picker