tests/net_inet/test_tls_sites: Update for ussl.SSLContext.
tests/net_inet/test_tls_sites: Update for ussl.SSLContext.

Primary interface for ussl modules is now ussl.SSLContext object.

Change-Id: Ie08d584883c937fb1e50351e50c52d1fd1c3a0f8
Signed-off-by: Paul Sokolovsky <9dc5061f178bb11813e14f1ed02ba27eaf21fa5d@users.sourceforge.net>

pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython