Fix typo in comment
diff --git a/Lib/nntplib.py b/Lib/nntplib.py
index 8bf78a3..618e4b8 100644
--- a/Lib/nntplib.py
+++ b/Lib/nntplib.py
@@ -565,7 +565,7 @@
         return resp
 
 
-# Test retrieval when rubn as a script.
+# Test retrieval when run as a script.
 # Assumption: if there's a local news server, it's called 'news'.
 # Assumption: if user queries a remote news server, it's named
 # in the environment variable NNTPSERVER (used by slrn and kin)