SPDY: removed state to check first SETTINGS frame.

SPDY: removed state to check first SETTINGS frame.

That code was based on misunderstanding of spdy specification about
configuration applicability in the SETTINGS frames.  The original
interpretation was that configuration is assigned for the whole
SPDY connection, while it is only for the endpoint.

Moreover, the strange thing is that specification forbids multiple
entries in the SETTINGS frame with the same ID even if flags are
different.  As a result, Chrome sends two SETTINGS frames: one with
its own configuration, and another one with configuration stored
for a server (when the FLAG_SETTINGS_PERSIST_VALUE flags were used
by the server).

To simplify implementation we refuse to use the persistent settings
feature and thereby avoid all the complexity related with its proper
support.