Remove WKSuspendInBackground preference (#310)

* Remove WKSuspendInBackground preference

* Update README.md

Author: jcesarmobile

README.md

@@ -78,10 +78,12 @@ If `UseScheme` is set to yes, it will use the `HostName` value as the host of th
 
 Example `ionic://app`
 
-#### WKSuspendInBackground
+#### WKSuspendInBackground (Removed in 2.4.0)
+
+This preference has been removed in 2.4.0 version of the plugin as it relied on a private API. Apps relying on this preference will not work as intended after the update. It will act as the previous default value, which was true.
 
 ```xml
-<preference name="WKSuspendInBackground" value="false" />
+<preference name="WKSuspendInBackground" value="true" />
 ```
 
 Whether to try to keep the server running when the app is backgrounded. Note: the server will likely be suspended by the OS after a few minutes. In particular, long-lived background tasks are not allowed on iOS outside of select audio and geolocation tasks.

src/ios/CDVWKWebViewEngine.m

@@ -117,8 +117,6 @@ @interface CDVWKWebViewEngine ()
 // expose private configuration value required for background operation
 @interface WKWebViewConfiguration ()
 
-@property (setter=_setAlwaysRunsAtForegroundPriority:, nonatomic) bool _alwaysRunsAtForegroundPriority;
-
 @end
 
 
@@ -221,15 +219,9 @@ -(void)startServer
     int portNumber = [settings cordovaFloatSettingForKey:@"WKPort" defaultValue:8080];
 
     //enable suspend in background if set in config
-    BOOL suspendInBackground = [settings cordovaBoolSettingForKey:@"WKSuspendInBackground" defaultValue:YES];
+    BOOL suspendInBackground = YES;
     int waitTime = 10;
 
-    //extend default connection coalescing time when background enabled
-    if(!suspendInBackground){
-        NSLog(@"CDVWKWebViewEngine: Suspend in background disabled");
-        waitTime = 60;
-    }
-
     NSDictionary *options = @{
                               GCDWebServerOption_AutomaticallySuspendInBackground: @(suspendInBackground),
                               GCDWebServerOption_ConnectedStateCoalescingInterval: @(waitTime),
@@ -259,8 +251,6 @@ - (WKWebViewConfiguration*) createConfigurationFromSettings:(NSDictionary*)setti
         return configuration;
     }
 
-    //required to stop wkwebview suspending in background too eagerly (as used in background mode plugin)
-    configuration._alwaysRunsAtForegroundPriority = ![settings cordovaBoolSettingForKey:@"WKSuspendInBackground" defaultValue:YES];
     configuration.allowsInlineMediaPlayback = [settings cordovaBoolSettingForKey:@"AllowInlineMediaPlayback" defaultValue:YES];
     configuration.suppressesIncrementalRendering = [settings cordovaBoolSettingForKey:@"SuppressesIncrementalRendering" defaultValue:NO];
     configuration.allowsAirPlayForMediaPlayback = [settings cordovaBoolSettingForKey:@"MediaPlaybackAllowsAirPlay" defaultValue:YES];