bundle2: remove unnecessary try finally

This is no longer needed.

Differential Revision: https://phab.mercurial-scm.org/D708

mercurial/bundle2.py

@@ -505,7 +505,6 b' def _processpart(op, part):'
 
     The part is guaranteed to have been fully consumed when the function exits
     (even if an exception is raised)."""
-    try:
         handler = _gethandler(op, part)
         if handler is None:
             return
@@ -528,9 +527,6 b' def _processpart(op, part):'
                                            mandatory=False)
                 outpart.addparam(
                     'in-reply-to', pycompat.bytestr(part.id), mandatory=False)
-    finally:
-        pass
-
 
 def decodecaps(blob):
     """decode a bundle2 caps bytes blob into a dictionary