correct the order in the say assertion messages

The message from the example yields:
```
./spec/my_spec.lua:12: Expected property (table): {
  [name] = 'masiak'
  [age] = 32 } in:
(string) 'last_name'
```

After my tweak, it now prints:
```
./spec/my_spec.lua:12: Expected (table): {
  [name] = 'masiak'
  [age] = 32 } 
to have property: (string) 'last_name'
```
This might be due to my environment, running LuaJIT? but I thought I'd just share the patch here.