Simplified ignored? condition with JRuby

Author: hsbt

bundler/lib/bundler/stub_specification.rb

@@ -40,7 +40,7 @@ def ignored?
 
       # If we share GEM_HOME for all of Ruby platform, the platform specific gem always warn that specification.
       # ex `jruby-launcher` and CRuby
-      if platform == Gem::Platform::RUBY && RUBY_ENGINE != "jruby"
+      if RUBY_ENGINE != "jruby"
         warn "Source #{source} is ignoring #{self} because it is missing extensions"
       end