Remove RubyForge Hoe's setting

RubyForge is no available in usage and newer versions of Hoe no longer
defines or support it.

Author: luislavena

Rakefile

@@ -21,7 +21,6 @@ Hoe.plugin :git
 # Hoe.plugin :isolate
 
 hoe = Hoe.spec 'rubygems-update' do
-  self.rubyforge_name = 'rubygems'
   self.author         = ['Jim Weirich', 'Chad Fowler', 'Eric Hodel']
   self.email          = %w[[email protected]]
   self.readme_file    = 'README.rdoc'