Revert "email: add support for Server Name Indication (SNI)"

This reverts commit 02684c911b4c035404a856bf145d2f616c1d0b08.

It's causing NPE because of socket.close (see https://android-review.googlesource.com/#/c/89135/3)

Change-Id: I5c524db1ae23e6a9b8852014b2f10332ff32de61
Merge "Revert "email: add support for Server Name Indication (SNI)"" into cm-11.0
TRDS:[Email] Dark Email (1/2)

Change-Id: I7be2c501f818922da675cfd8d490e387afb9247b