Avoid using deprecated APIs on iOS 10.0+

Change-Id: Ic9dc6a24ef793a29c2652ad37bc11120e2e6ceef
Reviewed-by: Jake Petroules <jake.petroules@qt.io>

src/gui/util/qdesktopservices.cpp

@@ -177,6 +177,19 @@ void QOpenUrlHandlerRegistry::handlerDestroyed(QObject *handler)
     still fail to launch or fail to open the requested URL. This result will not be reported back
     to the application.
 
+    \warning URLs passed to this function on iOS will not load unless their schemes are
+    listed in the \c LSApplicationQueriesSchemes key of the application's Info.plist file.
+    For more information, see the Apple Developer Documentation for
+    \l{https://developer.apple.com/documentation/uikit/uiapplication/1622952-canopenurl}{canOpenURL(_:)}.
+    For example, the following lines enable URLs with the HTTPS scheme:
+
+    \code
+    <key>LSApplicationQueriesSchemes</key>
+    <array>
+        <string>https</string>
+    </array>
+    \endcode
+
     \sa setUrlHandler()
 */
 bool QDesktopServices::openUrl(const QUrl &url)

src/plugins/platforms/ios/qiosservices.mm

@@ -55,11 +55,13 @@ bool QIOSServices::openUrl(const QUrl &url)
         return openDocument(url);
 
     NSURL *nsUrl = url.toNSURL();
+    UIApplication *application = [UIApplication sharedApplication];
 
-    if (![[UIApplication sharedApplication] canOpenURL:nsUrl])
+    if (![application canOpenURL:nsUrl])
         return false;
 
-    return [[UIApplication sharedApplication] openURL:nsUrl];
+    [application openURL:nsUrl options:@{} completionHandler:nil];
+    return true;
 }
 
 bool QIOSServices::openDocument(const QUrl &url)