src/pmdas/GNUmakefile: be more careful about pmcd.conf access control clause
src/pmdas/GNUmakefile: be more careful about pmcd.conf access control clause

If the platform does not support unix-domain sockets (like Windows),
then use localhost instead of local:* for the allow access control
clause when constructing pmcd.conf.

adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp