Don’t try to set tenant in middleware if it is already set.

[jaydensmith]

In my application, I have another middleware that sets the tenant based on a header if present. This change is necessary to prevent overriding the previous middleware.

[lorinkoz]

Sounds reasonable. Would you please add a small test to cover the new behavior?

[lorinkoz]

Quick update: I plan on also providing middleware for different types of tenant routing in v1, applying some ideas I used in another package. Stay tuned.

However, the final approach should be that, when multiple routing middleware are combined, the last one prevails.