~/path/to/lock should be actual path value

[lanzafame]

Got this when attempting to run ipfs-cluster-service for the first time:

15:57:21.995 ERROR    service: could not obtain execution lock.  If no other process
is running, remove ~/path/to/lock, or make sure that the config folder is
writable for the user running ipfs-cluster.  Run with -d for more information
about the error lock.go:37
error acquiring execution lock: could not obtain execution lock

Would be better if the message contained the actual path to the lock.