Fallback to first remote task info when no folder is open

Previous behavior was to fallback to local. It makes more sense to fallback to the the first remote details instead
Related to microsoft/vscode-docker#2350

src/vs/workbench/contrib/tasks/browser/abstractTaskService.ts

@@ -1586,11 +1586,14 @@ export abstract class AbstractTaskService extends Disposable implements ITaskSer
 			this.contextService, this.environmentService,
 			AbstractTaskService.OutputChannelId, this.fileService, this.terminalInstanceService,
 			this.pathService, this.viewDescriptorService, this.logService,
-			(workspaceFolder: IWorkspaceFolder) => {
-				if (!workspaceFolder) {
+			(workspaceFolder: IWorkspaceFolder | undefined) => {
+				if (workspaceFolder) {
+					return this._taskSystemInfos.get(workspaceFolder.uri.scheme);
+				} else if (this._taskSystemInfos.size > 0) {
+					return this._taskSystemInfos.values().next().value;
+				} else {
 					return undefined;
 				}
-				return this._taskSystemInfos.get(workspaceFolder.uri.scheme);
 			}
 		);
 	}

src/vs/workbench/contrib/tasks/browser/terminalTaskSystem.ts

@@ -635,7 +635,7 @@ export class TerminalTaskSystem implements ITaskSystem {
 			const folders = this.contextService.getWorkspace().folders;
 			workspaceFolder = folders.length > 0 ? folders[0] : undefined;
 		}
-		const systemInfo: TaskSystemInfo | undefined = this.currentTask.systemInfo = workspaceFolder ? this.taskSystemInfoResolver(workspaceFolder) : undefined;
+		const systemInfo: TaskSystemInfo | undefined = this.currentTask.systemInfo = this.taskSystemInfoResolver(workspaceFolder);
 
 		let variables = new Set<string>();
 		this.collectTaskVariables(variables, task);

src/vs/workbench/contrib/tasks/common/taskSystem.ts

@@ -125,7 +125,7 @@ export interface TaskSystemInfo {
 }
 
 export interface TaskSystemInfoResolver {
-	(workspaceFolder: IWorkspaceFolder): TaskSystemInfo | undefined;
+	(workspaceFolder: IWorkspaceFolder | undefined): TaskSystemInfo | undefined;
 }
 
 export interface ITaskSystem {