Fix glance_http HTTPS response issues

This commit is a dual of python-glanceclient change:
I3a973da3b962c7572ae0f61f6996bdd1f0048339

Also, a bad file descriptor error is caused by the socket being closed
to soon. This commit adds overloads close() for the
VerifiedHTTPSConnection subclass which will remove the reference to
socket before making the call in the base HTTPConnection.close(). This
will avoid socket being closed before the response body is read. The
socket will close when the response close is called.

Closes-Bug: #1272828

Change-Id: Ia30058bc4752489107b998bd44d38c27901cfe63
Merge "Fix glance_http HTTPS response issues"