Use the upstream unf_ext again

The new version was released that includes our Solaris patch as well as Ruby 2.6 support.

Signed-off-by: Tim Smith <tsmith@chef.io>

Gemfile

@@ -8,7 +8,6 @@ gem 'ffi', '>= 1.9.14'
 group :omnibus do
   gem 'rb-readline'
   gem 'appbundler'
-  gem 'unf_ext', git: 'https://github.com/chef/ruby-unf_ext.git', ref: '55d872fb15f3a26e4ee8f8dbe7ba859c80d40383'
 end
 
 group :test do

omnibus/config/software/inspec.rb

@@ -22,7 +22,6 @@ name 'inspec'
 dependency 'ruby'
 dependency 'rubygems'
 dependency 'bundler'
-dependency 'unf_ext'
 
 license :project_license
 

omnibus/config/software/unf_ext.rb

@@ -1,19 +0,0 @@
-# override for unf_ext until
-# https://github.com/knu/ruby-unf_ext/pull/39
-# is merged (done!) and released (not as of March 2019)
-
-name 'unf_ext'
-
-dependency 'ruby'
-dependency 'rubygems'
-
-license :project_license
-default_version '55d872fb15f3a26e4ee8f8dbe7ba859c80d40383'
-source git: 'https://github.com/chef/ruby-unf_ext.git'
-
-build do
-  env = with_standard_compiler_flags(with_embedded_path)
-  delete "#{name}-*.gem"
-  gem "build #{name}.gemspec", env: env
-  gem "install #{name}-*.gem --no-document", env: env
-end