simplify the regex

Author: timfish

src/common.ts

@@ -29,8 +29,8 @@ export function stringToUUID(str: string): string {
 
 export function addDebugIdToSource(input: string, debugId: string): string {
   return input.replace(
-    /(\n*)?(\/\/# debugId=.+)?(\n*)?(\/\/# .+\n*)?$/,
-    `\n//# debugId=${debugId}\n$4`
+    /\n*(\/\/# debugId=.+)?\n*(\/\/# .+\n*)?$/,
+    `\n//# debugId=${debugId}\n$2`
   );
 }