make protocal an alias of protocol

Author: dorentus

lib/carrierwave/qiniu/configuration.rb

@@ -11,7 +11,7 @@ module Configuration
         add_config :qiniu_secret_key
         add_config :qiniu_block_size
         add_config :qiniu_protocol
-        add_config :qiniu_protocal
+        alias_config :qiniu_protocal, :qiniu_protocol
       end
     end
 
@@ -36,6 +36,22 @@ def #{name}
             end
           RUBY
         end
+
+      def alias_config(new_name, old_name)
+        class_eval <<-RUBY, __FILE__, __LINE__ + 1
+          def self.#{new_name}(value=nil)
+            self.#{old_name}(value)
+          end
+
+          def self.#{new_name}=(value)
+            self.#{old_name}=(value)
+          end
+
+          def #{new_name}
+            #{old_name}
+          end
+        RUBY
+      end
     end
   end
 end