Issue #18200: Update the stdlib (except tests) to use
ModuleNotFoundError.
diff --git a/Lib/quopri.py b/Lib/quopri.py
index e5bd010..63afc1d 100755
--- a/Lib/quopri.py
+++ b/Lib/quopri.py
@@ -13,7 +13,7 @@
 
 try:
     from binascii import a2b_qp, b2a_qp
-except ImportError:
+except ModuleNotFoundError:
     a2b_qp = None
     b2a_qp = None