CONTRIBUTING

wrapcommand: use functools.partial

Like the previous patch, this helps remove noises in traceback.

Practically, this removes another 6 lines in `rebase -s . -d .` traceback in
my setup:

   ....
   File "hg/mercurial/util.py", line 1118, in check
     return func(*args, **kwargs)
  -File "hg/mercurial/extensions.py", line 331, in closure
  -  return func(*(args + a), **kw)
   File "hg/mercurial/util.py", line 1118, in check
     return func(*args, **kwargs)
   File "fb-hgext/hgext3rd/fbhistedit.py", line 283, in _rebase
     return orig(ui, repo, **opts)
   File "hg/mercurial/util.py", line 1118, in check
     return func(*args, **kwargs)
  -File "hg/mercurial/extensions.py", line 331, in closure
  -  return func(*(args + a), **kw)
   File "hg/mercurial/util.py", line 1118, in check
     return func(*args, **kwargs)
   File "remotenames.py", line 633, in exrebasecmd
     ret = orig(ui, repo, **opts)
   File "hg/mercurial/util.py", line 1118, in check
     return func(*args, **kwargs)
  -File "hg/mercurial/extensions.py", line 331, in closure
  -  return func(*(args + a), **kw)
   File "hg/mercurial/util.py", line 1118, in check
     return func(*args, **kwargs)
   File "fb-hgext/hgext3rd/fbamend/__init__.py", line 453, in wraprebase
     return orig(ui, repo, **opts)
   File "hg/mercurial/util.py", line 1118, in check
     return func(*args, **kwargs)
   ....

Differential Revision: https://phab.mercurial-scm.org/D633

Our full contribution guidelines are in our wiki, please see:

https://www.mercurial-scm.org/wiki/ContributingChanges

If you just want a checklist to follow, you can go straight to

https://www.mercurial-scm.org/wiki/ContributingChanges#Submission_checklist

If you can't run the entire testsuite for some reason (it can be
difficult on Windows), please at least run `contrib/check-code.py` on
any files you've modified and run `python contrib/check-commit` on any
commits you've made (for example, `python contrib/check-commit
273ce12ad8f1` will report some style violations on a very old commit).