Trim key file

[jared2501]

If the encrypted-config-value.key file has a new line at the end of it the decryption fails with the confusing error about being unable to base64 decode. Vim is sometimes configured to insert new lines at the ends of files, which leads to hard to debug issues.

Proposed solution: since the second component of the string is base64 encoded it's able to be trimmed before being decoded.