Update ActionSheetMultipleStringPicker.m
Update ActionSheetMultipleStringPicker.m

With Swift, having self.initialSelection as (nonatomic, assign) resulted in EXC_BAD_ACCESS when initializing the picker and attempting to access the property. Changing to (nonatomic, strong) fixed the error.
jum/ActionSheetPicker,jum/ActionSheetPicker,tbaranes/ActionSheetPicker-3.0,ChronicStim/ActionSheetPicker,skywinder/ActionSheetPicker-3.0,ChronicStim/ActionSheetPicker,skywinder/ActionSheetPicker-3.0,tbaranes/ActionSheetPicker-3.0