debug: use default tree indentation of 12 pixels

fixes #10618

src/vs/workbench/parts/debug/electron-browser/debugViews.ts

@@ -30,7 +30,6 @@ import IDebugService = debug.IDebugService;
 
 const debugTreeOptions = (ariaLabel: string) => {
 	return <tree.ITreeOptions> {
-		indentPixels: 8,
 		twistiePixels: 20,
 		ariaLabel
 	};

src/vs/workbench/parts/debug/electron-browser/repl.ts

@@ -43,7 +43,6 @@ import {IPanelService} from 'vs/workbench/services/panel/common/panelService';
 const $ = dom.$;
 
 const replTreeOptions: tree.ITreeOptions = {
-	indentPixels: 8,
 	twistiePixels: 20,
 	ariaLabel: nls.localize('replAriaLabel', "Read Eval Print Loop Panel")
 };
@@ -57,8 +56,6 @@ export interface IPrivateReplService {
 	acceptReplInput(): void;
 }
 
-
-
 export class Repl extends Panel implements IPrivateReplService {
 	public _serviceBrand: any;