debian/pcp-export-zabbix-agent.install: add missing files
debian/pcp-export-zabbix-agent.install: add missing files

Recent packaging changes had broken the Debian build (install
actually).

Two files that used to be in pcp-export-zabbix-agent had migrated
to the pcp package ... put 'em back where they belong.

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