wireproto: turn an 'except' into a 'finally' as suggest by the comment

Look! More hidden footprints!

mercurial/wireproto.py

@@ -807,11 +807,8 b' def stream(repo, proto):'
                 else:
                     for chunk in util.filechunkiter(sopener(name), limit=size):
                         yield chunk
-        # replace with "finally:" when support for python 2.4 has been dropped
-        except Exception:
+        finally:
             sopener.mustaudit = oldaudit
-            raise
-        sopener.mustaudit = oldaudit
 
     return streamres(streamer(repo, entries, total_bytes))