Wrong configuration of dynamic routes in core.py

[Tushar]

Describe the bug
For a path like /home/<user> the associated function should take user as a variable.

https://github.com/BlitzKraft/saythanks.io/blob/master/saythanks/core.py#L120

The URL https://saythanks.io/inbox/export/csv is giving an error due to this.

[Tushar]

I am fixing this as well