drgn.internal.repl: also catch AttributeError in enhanced REPL attempt

I didn't see this in practice, it's mostly out of paranoia. In
particular, if _pyrepl.readline._setup() goes away, this will catch it.

Signed-off-by: Omar Sandoval <[email protected]>

drgn/internal/repl.py

@@ -39,7 +39,7 @@ def interact(local: Dict[str, Any], banner: str) -> None:
         print(banner, file=sys.stderr)
         run_multiline_interactive_console(console)
 
-except (ModuleNotFoundError, ImportError):
+except (ModuleNotFoundError, ImportError, AttributeError):
     import code
     import readline