backButton fixed in ios

lib/ios/RNNBackButtonOptions.m

 @implementation RNNBackButtonOptions
 
 - (void)applyOn:(UIViewController *)viewController {
-	UIImage *image = self.image ? [RCTConvert UIImage:self.image] : nil;
-	[viewController.navigationController.navigationBar setBackIndicatorImage:image];
-	[viewController.navigationController.navigationBar setBackIndicatorTransitionMaskImage:image];
+	if (self.image) {
+		UIImage *image = self.image ? [RCTConvert UIImage:self.image] : nil;
+		[viewController.navigationController.navigationBar setBackIndicatorImage:image];
+		[viewController.navigationController.navigationBar setBackIndicatorTransitionMaskImage:image];
+	}
 	
-	if ([self.hideTitle boolValue]) {
-		self.title = @"";
+	if (self.visible) {
+		viewController.navigationItem.hidesBackButton = ![self.visible boolValue];
+		
+		if (![self.visible boolValue]) {
+			self.title = @"";
+		}
 	}
 	
 	if (self.title) {
 		
 		viewController.navigationItem.backBarButtonItem = backItem;
 	}
-	
-	viewController.navigationItem.hidesBackButton = ![self.visible boolValue];
 }
 
 @end

lib/ios/RNNTopBarOptions.m

 		_navigationButtons = [[RNNNavigationButtons alloc] initWithViewController:(RNNRootViewController*)viewController];
 		[_navigationButtons applyLeftButtons:self.leftButtons rightButtons:self.rightButtons];
 	}
-
-	UIImage *image = self.backButton.image ? [RCTConvert UIImage:self.backButton.image] : nil;
-	[viewController.navigationController.navigationBar setBackIndicatorImage:image];
-	[viewController.navigationController.navigationBar setBackIndicatorTransitionMaskImage:image];
-	
-	if (![self.backButton.visible boolValue]) {
-		self.backButton.title = @"";
-	}
-	
-	if (self.backButton.title) {
-		UIBarButtonItem *backItem = [[UIBarButtonItem alloc] initWithTitle:self.backButton.title
-																	 style:UIBarButtonItemStylePlain
-																	target:nil
-																	action:nil];
-		
-		viewController.navigationItem.backBarButtonItem = backItem;
-	}
-	
-	viewController.navigationItem.hidesBackButton = ![self.backButton.visible boolValue];
 }
 
 -(void)storeOriginalTopBarImages:(UIViewController*)viewController {