fix crash when NetworkService creates lazy in background thread (globalinit_*_func0)

Sources/Extensions/NetworkService/NetworkService+ActivityIndicator.swift

@@ -26,9 +26,12 @@ extension NetworkService {
 
     /// Let netwrok service automatically show / hide activity indicator
     public func bindActivityIndicator() -> Disposable {
-        return requestCount
-            .map { $0 != 0 }
-            .drive(UIApplication.shared.rx.isNetworkActivityIndicatorVisible)
+        // Fatal error: `drive*` family of methods can be only called from `MainThread`
+        return DispatchQueue.main.sync {
+            requestCount
+                .map { $0 != 0 }
+                .drive(UIApplication.shared.rx.isNetworkActivityIndicatorVisible)
+        }
     }
 
 }