LU-5380 at: net AT after connect

LU-5380 at: net AT after connect

Once connected, the previously gathered AT statistics is not valid
anymore because may reflect other routing, etc. The connect by itself
could take a long time due to different reasons (e.g. server was not
ready) and net latency got very high (see import_select_connection())
what does not reflect the current situation.

Take into account only the current (re-)CONNECT rpc latency.

Signed-off-by: Vitaly Fertman <vitaly_fertman@xyratex.com>
Signed-off-by: Alexander Boyko <alexander_boyko@xyratex.com>
Xyratex-bug-id: MRP-1285
Change-Id: I6edc0e232a92319e7c8535aced28fe1ad3436c54
Reviewed-on: http://review.whamcloud.com/11155
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Liang Zhen <liang.zhen@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>