Description of problem:
With the rate limit change came a behavioural change for rest requests - the api key is required.
This did not get updated for the tmx import/export features of Zanata and results in a 401.

Version-Release number of selected component (if applicable):
Dev

How reproducible:
Easy always

Steps to Reproduce:
1. Go to any project version
2. select a language and press export to tmx

or

1. As admin, go to Administration > Translation Memory
2. Create or select a TM entry
3. Press the import button, select a file, press import

Actual results:
401 Not Authorized

Expected results:
If the user has a key, this should not appear.

Additional info:
The tm export shows the "key required" error, but the TM import does not.