Merge pull request #2089 from yunline/fix-gen_stubs.py

fix gen_stubs.py

Author: andrewhong04

buildconfig/stubs/gen_stubs.py

@@ -48,7 +48,7 @@
     "surface",
     "surflock",
     "sysfont",
-    "_debug"
+    "_debug",
     "system",
 ]