Fix for small bug in Ruby plugin/gem (InvalidEndpoint Error)

[eskim0]

Just a quick post in case someone else runs into the same issue I did
- was getting a problem with the POST in the ruby code for Zeep, an
"InvalidEndpoint" error. Dug into it a little and found a trailing
"/" on line 10 of zeep_it/lib/zeep/messaging.rb, which was causing the
URL to generate with two forward slashes after the root domain. It
had generated:

https://api.zeepmobile.com//messaging/2008-07-14/send_message

So, line 10 should read:

@@base_url = 'https://api.zeepmobile.com

I was using the zeep_it gem/plugin (as plugin) from http://github.com/ychaker/zeep_it
- but I understand the correction reflects a change to the root code
provided by Zeep (http://www.zeepmobile.com/developers/clients/
messaging/ruby/rdoc/), in the Zeep::Base module, so I expect this
reflects a potential issue in that codebase as well.

Both my Mac OSX (10.6) and Ubuntu Linux servers were affected -
perhaps other environments are not, or perhaps earlier versions of
Ruby are not. I'm on Ruby 1.8.7.