sysutils/py-salt: Restore install arguments post r427901 to fix syspaths.py

Without PYDISTUTILS_INSTALL_TARGET setting the install arguments, salt
will be built with an invalid syspaths.py, particularly if installed
somewhere other than /usr/local.

As of 2016.11.0, the arguments caused an error, which was traced back to
https://github.com/saltstack/salt/pull/31097/files.
The removed code was deprecated, but included instructions on how to
make the arguments continue to work: simply move them earlier in the
command (ie., "python setup.py <args> install" instead of
"python setup.py install <args>").

PR: 215885
Submitted by: Erick Turnquist <jhujhiti@adjectivism.org>
Approved by: Christer Edwards (maintainer)
MFH: 2017Q1