fix(ios): return when user navigates to the same page (#760)

Author: okwasniewski

ios/Fabric/RNCPagerViewComponentView.mm

@@ -192,6 +192,10 @@ - (void)enableSwipe {
 - (void)goTo:(NSInteger)index animated:(BOOL)animated {
     NSInteger numberOfPages = _nativeChildrenViewControllers.count;
 
+    if (index == _currentIndex) {
+        return;
+    }
+    
     [self disableSwipe];
 
     _destinationIndex = index;

ios/ReactNativePageView.m

@@ -243,6 +243,10 @@ - (void)enableSwipe {
 - (void)goTo:(NSInteger)index animated:(BOOL)animated {
     NSInteger numberOfPages = self.reactSubviews.count;
 
+    if (index == _currentIndex) {
+        return;
+    }
+    
     [self disableSwipe];
 
     _destinationIndex = index;