Removed techtv data source as it frequently fails to render
Removed techtv data source as it frequently fails to render

The MySQL host frequently throws an error about having too many open connections, requiring the `flush-hosts` command to be executed and making the pillar rendering fail. Since this source is not frequently used and is likely to be retired soon I removed it from the pillar data, in favor of manually updating the credentials as needed.

mitodl/salt-ops,mitodl/salt-ops