Be slightly clearer about what happens when we try to enable output with no matching...

[nageru] / bmusb

diff --git a/bmusb b/bmusb
index 36ed21d8e2c4590d7f6489efc05489f21da8d5be..b18056fe32dd46134d7f12165bfa083378f2d9bb 160000 (submodule)
--- a/bmusb
+++ b/bmusb
@@ -1 +1 @@
-Subproject commit 36ed21d8e2c4590d7f6489efc05489f21da8d5be
+Subproject commit b18056fe32dd46134d7f12165bfa083378f2d9bb