changegroup: deduplicate 'getlocalchangegroup' The two functions 'getlocalchangegroup' and 'getchangegroup' have been strictly identical for multiple years ('getchangegroup' had a deprecated docstring) We'll drop one of them (getlocalchangegroup, since it has the longest name). However, we needs to migrate all users of the dropped one to the new one before we can deprecate it. In the mean time we drop one of the duplicated definition and the outdated docstring.