debug: do not listen on launch.json changes, re-read it before debug start

fixes #47021

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

@@ -82,7 +82,6 @@ export class DebugService implements debug.IDebugService {
 	private debugType: IContextKey<string>;
 	private debugState: IContextKey<string>;
 	private breakpointsToSendOnResourceSaved: Set<string>;
-	private launchJsonChanged: boolean;
 	private firstSessionStart: boolean;
 	private skipRunningTask: boolean;
 	private previousState: debug.State;
@@ -698,7 +697,6 @@ export class DebugService implements debug.IDebugService {
 					this.allProcesses.clear();
 					this.model.getBreakpoints().forEach(bp => bp.verified = false);
 				}
-				this.launchJsonChanged = false;
 
 				let config: debug.IConfig, compound: debug.ICompound;
 				if (!configOrName) {
@@ -1081,12 +1079,9 @@ export class DebugService implements debug.IDebugService {
 
 				return new TPromise<void>((c, e) => {
 					setTimeout(() => {
-						// Read the configuration again if a launch.json has been changed, if not just use the inmemory configuration
 						let config = process.configuration;
-
 						const launch = process.session.root ? this.configurationManager.getLaunch(process.session.root.uri) : undefined;
-						if (this.launchJsonChanged && launch) {
-							this.launchJsonChanged = false;
+						if (launch) {
 							config = launch.getConfiguration(process.configuration.name) || config;
 							// Take the type from the process since the debug extension might overwrite it #21316
 							config.type = process.configuration.type;
@@ -1303,13 +1298,9 @@ export class DebugService implements debug.IDebugService {
 		}
 
 		fileChangesEvent.getUpdated().forEach(event => {
-
 			if (this.breakpointsToSendOnResourceSaved.delete(event.resource.toString())) {
 				this.sendBreakpoints(event.resource, true).done(null, errors.onUnexpectedError);
 			}
-			if (strings.endsWith(event.resource.toString(), '.vscode/launch.json')) {
-				this.launchJsonChanged = true;
-			}
 		});
 	}