commands/command_untrack.go: print fixed usage msg

In commit ff0f378778f46f9b87f78d68f797a194cf32d6cf of
PR #4781 a usage message for the "git lfs untrack" command was
made translatable; however, since this only contains a fixed
command example which references the man pages, we can avoid
translating it.

commands/command_untrack.go

@@ -18,7 +18,7 @@ func untrackCommand(cmd *cobra.Command, args []string) {
 	installHooks(false)
 
 	if len(args) < 1 {
-		Print(tr.Tr.Get("git lfs untrack <path> [path]*"))
+		Print("git lfs untrack <path> [path]*")
 		return
 	}