[BRE-186] Updated SDK version to 4.39.0 for Sprint Link release.
[BRE-186] Updated SDK version to 4.39.0 for Sprint Link release.

Reviewers: tyler, bigly, davidcruz

Reviewed By: davidcruz

Subscribers: tyler

Differential Revision: https://phabricator.bitgo.com/D10129

BitGo/BitGoJS,BitGo/BitGoJS,BitGo/BitGoJS,BitGo/BitGoJS