message: Cleared image if prop removed
diff: @@ -74,6 +74,10 @@ using namespace facebook::react;
  self.button.accessibilityIdentifier = testID;
  }
  }
  + NSString *uri = [[NSString alloc] initWithUTF8String:newViewProps.image.uri.c_str()];
  + if (![uri length]) {
  + _button.image = nil;
  + }
  [super updateProps:props oldProps:oldProps];
  }
  