Fixes performance issue introduced in 3.0.6 (issue #6695)

activerecord/lib/active_record/attribute_methods/read.rb

@@ -84,9 +84,11 @@ def define_read_method(symbol, attr_name, column)
       # Returns the value of the attribute identified by <tt>attr_name</tt> after it has been typecast (for example,
       # "2004-12-12" in a data column is cast to a date object, like Date.new(2004, 12, 12)).
       def read_attribute(attr_name)
-        send "_#{attr_name}"
-      rescue NoMethodError
-        _read_attribute attr_name
+        if respond_to? "_#{attr_name}"
+          send "_#{attr_name}"
+        else
+          _read_attribute attr_name
+        end
       end
 
       def _read_attribute(attr_name)