LP#1066131: srfsh.py should not require opensrf.settings

Update srfsh.py to connect to the opensrf network without automatically
reading the opensrf.setting server data.  This allows srfsh.py to run a
non-private network.

Signed-off-by: Bill Erickson <berick@esilibrary.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>