path-suboption: use str for "delta_reuse_policy" suboptions

That second argument refer to an attribute and do not needs to be bytes.

mercurial/utils/urlutil.py

@@ -758,7 +758,7 b' DELTA_REUSE_POLICIES_NAME = dict(i[::-1]'
 
 @pathsuboption(
     b'pulled-delta-reuse-policy',
-    b'delta_reuse_policy',
+    'delta_reuse_policy',
     display=DELTA_REUSE_POLICIES_NAME.get,
 )
 def delta_reuse_policy(ui, path, value):