[collectd] inconsistent documentation wrt Collectd::Plugin{,s}

[Michael Shigorin]

	Hello Florian,
seems like the source code of collectd-4.9.1 references
Collectd::Plugins while collectd-perl(5) mentions
Collectd::Plugin -- which results in 

---
Can't locate
Collectd/Plugin/OpenVZ.pm in @INC (@INC contains: /usr/lib/perl5/vendor_perl
/etc/perl5 /usr/lib/perl5/x86_64-linux /usr/lib/perl5
/usr/local/lib/perl5/site_perl/5.8.9/x86_64-linux
/usr/local/lib/perl5/site_perl/5.8.9 /usr/local/lib/perl5/site_perl
/usr/lib/perl5/vendor_perl/x86_64-linux /usr/lib/perl5/vendor_perl
/usr/lib/perl5/vendor_perl .)
---

as reported by ALT Linux package user who had to 
ln -s Plugins /usr/lib/perl5/vendor_perl/Collectd/Plugin
to get it working; bug report in Russian can be found here:
https://bugzilla.altlinux.org/show_bug.cgi?id=23235

Could you please clarify what was intended and fix the
discrepancy?

Thanks in advance, and thanks yet another time for collectd!

-- 
 ---- WBR, Michael Shigorin <mike at altlinux.ru>
  ------ Linux.Kiev http://www.linux.kiev.ua/