remove rubygems_version

this will be set by the actual version that builds it
http://guides.rubygems.org/specification-reference/#rubygemsversion

Author: Jerry Cheung

net-ldap.gemspec

@@ -30,7 +30,6 @@ the most recent LDAP RFCs (4510-4519, plutions of 4520-4532).}
   s.rdoc_options = ["--main", "README.rdoc"]
   s.require_paths = ["lib"]
   s.required_ruby_version = Gem::Requirement.new(">= 1.9.3")
-  s.rubygems_version = %q{1.5.2}
   s.summary = %q{Net::LDAP for Ruby (also called net-ldap) implements client access for the Lightweight Directory Access Protocol (LDAP), an IETF standard protocol for accessing distributed directory services}
 
   if s.respond_to? :specification_version then