avoid duplicate dependency

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

@@ -55,8 +55,7 @@ import { IWorkspace } from 'vs/platform/workspace/common/workspace';
 import { IKeybindingService } from 'vs/platform/keybinding/common/keybinding';
 import { ContextKeyExpr, RawContextKey, IContextKeyService, IContextKey } from 'vs/platform/contextkey/common/contextkey';
 import { IActivityService } from 'vs/workbench/services/activity/common/activityService';
-import { IViewletService } from 'vs/workbench/services/viewlet/browser/viewletService';
-import { ViewletService } from 'vs/workbench/services/viewlet/browser/viewletService';
+import { IViewletService, ViewletService } from 'vs/workbench/services/viewlet/browser/viewletService';
 import { FileService } from 'vs/workbench/services/files/electron-browser/fileService';
 import { IFileService } from 'vs/platform/files/common/files';
 import { IConfigurationResolverService } from 'vs/workbench/services/configurationResolver/common/configurationResolver';