largefiles: reference `mercurial.configitems.dynamicdefault` directly

Pytype was unable to see `dynamicdefault` on `eh.configitem`.  This is clearer
anyway.

hgext/largefiles/__init__.py

@@ -107,6 +107,7 b' command.'
 
 from mercurial import (
     cmdutil,
+    configitems,
     extensions,
     exthelper,
     hg,
@@ -135,7 +136,7 b' eh.merge(proto.eh)'
 eh.configitem(
     b'largefiles',
     b'minsize',
-    default=eh.configitem.dynamicdefault,
+    default=configitems.dynamicdefault,
 )
 eh.configitem(
     b'largefiles',