[201811][swss] advance submodule head

swss:
* c9efae8 2023-01-25 | [201811][portinit] Do not call GET on SAI_PORT_ATTR_SPEED when AUTONEG is enabled (sonic-net#2484) (sonic-net#2640) (github/201811) [Ying Xie]
* ab785d8 2020-10-02 | remove FDB entires of BridgePort before removing the BridgePort (sonic-net#1451) [madhanmellanox]

Signed-off-by: Ying Xie <[email protected]>

Author: yxieca