proto/invoice -> bgpwtf/invoice/proto

Change-Id: I5d25864046665e4b0e57ec62a29797fbce6ed3cb
diff --git a/bgpwtf/invoice/calc.go b/bgpwtf/invoice/calc.go
index 5df763f..9c411da 100644
--- a/bgpwtf/invoice/calc.go
+++ b/bgpwtf/invoice/calc.go
@@ -3,7 +3,7 @@
 import (
 	"time"
 
-	pb "code.hackerspace.pl/hscloud/proto/invoice"
+	pb "code.hackerspace.pl/hscloud/bgpwtf/invoice/proto"
 )
 
 func calculateInvoiceData(p *pb.Invoice) {