What is the best practice for migrating table when a member of a struct is added? For some structs, I have had no problems adding members, but for others I have. I get this error message: 

```
$cleos get table <account> <contract> <table>
2628662ms thread-0   main.cpp:2552                 main                 ] Failed with error: Out of Range (8)
read datastream of length 16 over by 1
error unpacking uint32_t

```

This occurred after I added a uint32\_t member to the table struct. Is there a way to configure the migration to the new table so that I don't have start over? I would want to default the value to zero or some other value.