[202012][swss]: Submodule update for SWSS

Include following commits:
- c98b9f09 [202012][orchagent]: Get bridge port ID from FDBOrch cache instead of SAI API sonic-net#2657 (sonic-net#2658)
- 59886b8f [MuxOrch] Enabling neighbor when adding in active state (sonic-net#2601)

Signed-off-by: Lawrence Lee <lawlee@microsoft.com>