net: add specific error message for disabled SSLv3 fallback.

This change adds a specific error message for the error added in r299567. This
is because adding strings makes a change harder to merge to branches thus these
parts were split into this CL.

(Was reviewed as part of r299567 -- just split for landing.)


Review URL:

Cr-Commit-Position: refs/heads/master@{#299593}
2 files changed