Use async method for network calls, trying to fix a crash

app/src/main/java/eu/kanade/tachiyomi/data/network/NetworkHelper.kt

@@ -1,12 +1,10 @@
 package eu.kanade.tachiyomi.data.network
 
 import android.content.Context
-import okhttp3.Cache
+import okhttp3.*
-import okhttp3.OkHttpClient
-import okhttp3.Request
-import okhttp3.Response
 import rx.Observable
 import rx.subscriptions.Subscriptions
+import timber.log.Timber
 import java.io.File
 import java.io.IOException
 
@@ -43,20 +41,30 @@ class NetworkHelper(context: Context) {
     fun request(request: Request, client: OkHttpClient = defaultClient): Observable<Response> {
         return Observable.create { subscriber ->
             val call = client.newCall(request)
-            subscriber.add(Subscriptions.create { call.cancel() })
+            subscriber.add(Subscriptions.create {
+                call.cancel()
+                Timber.i("Cancel call on thread ${Thread.currentThread().id}")
+            })
 
-            try {
+            call.enqueue(object : Callback {
-                val response = call.execute()
+                override fun onResponse(call: Call, response: Response) {
                     if (!subscriber.isUnsubscribed) {
-                    subscriber.add(Subscriptions.create { response.body().close() })
+                        subscriber.add(Subscriptions.create {
+                            response.body().close()
+                            Timber.i("Close body on thread ${Thread.currentThread().id}")
+                        })
                         subscriber.onNext(response)
+                        Timber.i("Emit response on thread ${Thread.currentThread().id}")
                         subscriber.onCompleted()
                     }
-            } catch (error: IOException) {
+                }
+
+                override fun onFailure(call: Call, error: IOException) {
                     if (!subscriber.isUnsubscribed) {
                         subscriber.onError(error)
                     }
                 }
+            })
         }
     }