Switch to RCTJavaScriptWillStartLoadingNotification (#803)

fixes #800 #797

ios/RCCLightBox.m

@@ -65,7 +65,7 @@ const NSInteger kLightBoxTag = 0x101010;
         [self.reactView.contentView.layer addObserver:self forKeyPath:@"frame" options:0 context:nil];
         [self.reactView.contentView.layer addObserver:self forKeyPath:@"bounds" options:0 context:NULL];
         
-//        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onRNReload) name:RCTReloadNotification object:nil];
+        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onRNReload) name:RCTJavaScriptWillStartLoadingNotification object:nil];
     }
     return self;
 }

ios/RCCNotification.m

@@ -32,7 +32,7 @@
         [self.reactView.contentView.layer addObserver:self forKeyPath:@"frame" options:0 context:nil];
         [self.reactView.contentView.layer addObserver:self forKeyPath:@"bounds" options:0 context:NULL];
         
-//        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onRNReload) name:RCTReloadNotification object:nil];
+        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onRNReload) name:RCTJavaScriptWillStartLoadingNotification object:nil];
         
         if ([params[@"dismissWithSwipe"] boolValue])
         {

ios/RCCViewController.m

@@ -145,7 +145,7 @@ const NSInteger TRANSPARENT_NAVBAR_TAG = 78264803;
     
     [self setStyleOnInit];
     
-//    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onRNReload) name:RCTReloadNotification object:nil];
+    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onRNReload) name:RCTJavaScriptWillStartLoadingNotification object:nil];
     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onCancelReactTouches) name:RCCViewControllerCancelReactTouchesNotification object:nil];
     
     // In order to support 3rd party native ViewControllers, we support passing a class name as a prop mamed `ExternalNativeScreenClass`