修正没有配置 override 时报错的问题

src/excel-exporter/ExcelExporterApplication.ts

@@ -18,7 +18,7 @@ export interface Configurations {
 	output: {
 		[key: string]: ExporterConfigs,
 	}
-	override: Record<string, string>,
+	override?: Record<string, string>,
 }
 
 
@@ -58,9 +58,11 @@ export class ExcelExporterApplication {
 			let sheets = this.parser.parse_xlsl(file);
 			const base = path.basename(file).replace(/\.xlsx?$/, '');
 			for (const name in sheets) {
-				const override = this.configs.override[`${base}/${name}`];
 				const table = sheets[name];
+				if (this.configs.override) {
+					const override = this.configs.override[`${base}/${name}`];
 					table.output = override;
+				}
 				this.tables[name] = table;
 			}
 		}