fix(openURL): Use correct property name for readyState (#1581)

Closes #1580.

Author: dpogue

CordovaLib/Classes/Private/Plugins/CDVHandleOpenURL/CDVHandleOpenURL.m

@@ -64,7 +64,7 @@ - (void)processOpenUrl:(NSURL*)url pageLoaded:(BOOL)pageLoaded
     };
 
     if (!pageLoaded) {
-        NSString* jsString = @"document.readystate";
+        NSString* jsString = @"document.readyState";
         [self.webViewEngine evaluateJavaScript:jsString
                              completionHandler:^(id object, NSError* error) {
             if ((error == nil) && [object isKindOfClass:[NSString class]]) {