Fix iOS 9 setBadgeColor exception (#4270)

lib/ios/UIViewController+RNNOptions.m

@@ -87,7 +87,9 @@ const NSInteger BLUR_STATUS_TAG = 78264801;
 }
 
 - (void)rnn_setTabBarItemBadgeColor:(UIColor *)badgeColor {
-	self.tabBarItem.badgeColor = badgeColor;
+	if (@available(iOS 10.0, *)) {
+		self.tabBarItem.badgeColor = badgeColor;
+	}
 }
 
 - (void)rnn_setStatusBarStyle:(NSString *)style animated:(BOOL)animated {