typo in packet forward middleware module name

[hallazzang]

ibc-apps/middleware/packet-forward-middleware/packetforward/types/keys.go

Line 7 in 64ec449

ModuleName = "packetfowardmiddleware"

This should be "packetforwardmiddleware"(missing r)

[reecepbcups]

this can not be fixed due to being in production on so many networks. must remain as is.

[hallazzang]

@reecepbcups I understand. Just wanted to make sure everyone's aware of this, hopefully fix it in the future.