fixes a nodoc which swallowed the documentation for the rest of the methods [ci skip]

activerecord/lib/active_record/core.rb

@@ -232,8 +232,7 @@ def init_with(coder)
     # The dup method does not preserve the timestamps (created|updated)_(at|on).
     
     ##
-    # :nodoc:
-    def initialize_dup(other)
+    def initialize_dup(other) # :nodoc:
       cloned_attributes = other.clone_attributes(:read_attribute_before_type_cast)
       self.class.initialize_attributes(cloned_attributes)