Closing client before initializing a new one.

Author: yasirfolio3

ios/Classes/SwiftOptimizelyFlutterSdkPlugin.swift

@@ -90,8 +90,10 @@ public class SwiftOptimizelyFlutterSdkPlugin: NSObject, FlutterPlugin {
  }
 
  // Delete old user context
- userContextsTracker[sdkKey] = nil
  userContextsTracker.removeValue(forKey: sdkKey)
+ // Close and remove old client
+ getOptimizelyClient(arguments: call.arguments)?.close()
+ optimizelyClientsTracker.removeValue(forKey: sdkKey)
 
  // Creating new instance
  let optimizelyInstance = OptimizelyClient(sdkKey:sdkKey, eventDispatcher: eventDispatcher, periodicDownloadInterval: periodicDownloadInterval)