Refactor conditions for allowing plugins into a new method: Site#plguin_allowed?

lib/jekyll/site.rb

@@ -98,12 +98,16 @@ module Jekyll
 
     def require_gems
       self.gems.each do |gem|
-        if whitelist.include?(gem) || !self.safe
+        if plugin_allowed?(gem)
           require gem
         end
       end
     end
 
+    def plugin_allowed?(name)
+      whitelist.include?(gem_name) || !self.safe
+    end
+
     def whitelist
       @whitelist ||= Array[self.config['whitelist']].flatten || []
     end