Fix wanlist typo in prometheus metric name
Fix wanlist typo in prometheus metric name

This will be a breaking change for anyone who is currently monitoring
the `ipfs_bitswap_wanlist_total` prometheus stat

License: MIT
Signed-off-by: Andrew Chin <09c3fe443cd90255b3ab6945ab331bb5cdf11ccb@eminence32.net>

kyledrake/go-ipfs,ianopolous/go-ipfs,Luzifer/go-ipfs,chriscool/go-ipfs,chriscool/go-ipfs,OpenBazaar/go-ipfs,MichaelMure/go-ipfs,chriscool/go-ipfs,WilliButz/go-ipfs,Luzifer/go-ipfs,Quantomicus/go-ipfs,MichaelMure/go-ipfs,OpenBazaar/go-ipfs,JustinDrake/go-ipfs,JustinDrake/go-ipfs,kyledrake/go-ipfs,WilliButz/go-ipfs,OpenBazaar/go-ipfs,Quantomicus/go-ipfs,Luzifer/go-ipfs,MichaelMure/go-ipfs,kyledrake/go-ipfs,ianopolous/go-ipfs,ianopolous/go-ipfs,Quantomicus/go-ipfs,WilliButz/go-ipfs,JustinDrake/go-ipfs