-Content-Type. Stores all extracted data associated with its parameter name
-in the params table within the given message object. Multiple parameter
-values are stored as tables, ordinary ones as strings.
-@class function
-@name urldecode_message_body
-@param src Ltn12 source function
-@param msg HTTP message object
-@return Value indicating successful operation (not nil means "ok")
-@return String containing the error if unsuccessful
-@see parse_message_header
-]]
+Stores all extracted data associated with its parameter name in the params
+table within the given message object. Multiple parameter values are stored
+as tables, ordinary ones as strings.