[FAB-3020] fix client-server-flow doc typo
[FAB-3020] fix client-server-flow doc typo

Change-Id: If5cd625edd192251babfddaefbb953da084c40f0
Signed-off-by: Frank Han <acb99025a17469fd115223a77bf786cfce97fe03@126.com>

saadk10/fabric-ca,saadk10/fabric-ca