Revert "debug: remove support for top level debugServer"

This reverts commit fd9146fe.

src/vs/workbench/parts/debug/common/debug.ts

@@ -284,6 +284,7 @@ export interface IDebugConfiguration {
 
 export interface IGlobalConfig {
 	version: string;
+	debugServer?: number;
 	configurations: IConfig[];
 }
 

src/vs/workbench/parts/debug/node/debugConfigurationManager.ts

@@ -158,7 +158,12 @@ const schema: IJSONSchema = {
 				'type': 'object',
 				oneOf: []
 			}
-		}
+		},
+		// TODO@Isidor remove support for this in December
+		debugServer: {
+			type: 'number',
+			description: nls.localize('app.launch.json.debugServer', "DEPRECATED: please move debugServer inside a configuration.")
+		},
 	}
 };
 
@@ -259,6 +264,9 @@ export class ConfigurationManager implements debug.IConfigurationManager {
 
 			result = filtered.length === 1 ? filtered[0] : config.configurations[0];
 			result = objects.deepClone(result);
+			if (config && result && config.debugServer) {
+				result.debugServer = config.debugServer;
+			}
 		}
 
 		if (result) {