sandbox - do not double register electron service

src/vs/workbench/services/electron/electron-browser/electronService.ts

@@ -5,7 +5,6 @@
 
 import { IElectronService } from 'vs/platform/electron/node/electron';
 import { IMainProcessService } from 'vs/platform/ipc/common/mainProcessService';
-import { registerSingleton } from 'vs/platform/instantiation/common/extensions';
 import { createChannelSender } from 'vs/base/parts/ipc/common/ipc';
 
 export class ElectronService {
@@ -18,5 +17,3 @@ export class ElectronService {
 		return createChannelSender<IElectronService>(mainProcessService.getChannel('electron'), { context: mainProcessService.windowId });
 	}
 }
-
-registerSingleton(IElectronService, ElectronService, true);