rubygems update

[Paul M. Lambert]

I've opened a ticket with a patch to the rb-rubygems Portfile

This patch updates it to 0.9.1.  The current (0.9.0) and previous  
versions are being deprecated due to a security issue, and will stop  
working (for remote repository access) soon.

https://svn.macosforge.org/projects/macports/ticket/11277

If someone could verify the checksums, verify that it works, and  
commit it, I'd be grateful!

Paul