Bitbucket certificate download?

I am behind the proxy I get this warning when pushing from hg mercurial:

pushing to https://user@bitbucket.org/user/project\\
warning: bitbucket.org certificate with fingerprint bf:8b:48:f8:a5:22:43:fd:d2:7
9:bc:1e:6b:c7:19:20:a6:ef:c5:ed not verified (check hostfingerprints or web.cace
rts config setting)
http authorization required
realm: Bitbucket.org HTTP
After googling I have found out that valid bitbucket.org certificate fingerprint starts with 81:

I suspect that proxy is trying to fake the certificate to attack as man-in-the-middle to decrypt the traffic.

Is there a way I can download and install bitbucket.org certificate into mercurial hg and not getting a fake one from proxy?