[201811][utilities] advance submodule head (#7280)

Utilities:
* c96f19d 2021-04-08 | [load_minigraph]: Avoid starting PFCWD for EPMS devicetype (#1552) (HEAD -> 201811, github/201811) [Sumukha Tumkur Vani]

Signed-off-by: Ying Xie <ying.xie@microsoft.com>