Use the roaming and not the static runtime factory.

There is no reason to use the static factory, the roaming one is
strictly superior.

Change-Id: I10d62a7c34a1c6a000dbed38ff0bc9f2a55fb824
diff --git a/go/src/v.io/x/p2b/main.go b/go/src/v.io/x/p2b/main.go
index 9a098b8..a2c83b7 100644
--- a/go/src/v.io/x/p2b/main.go
+++ b/go/src/v.io/x/p2b/main.go
@@ -15,7 +15,7 @@
 	"v.io/v23"
 	"v.io/x/lib/vlog"
 	"v.io/x/p2b/vdl"
-	_ "v.io/x/ref/runtime/factories/static"
+	_ "v.io/x/ref/runtime/factories/roaming"
 )
 
 const usage = `