VOL-2342 Execute Close() in its own thread in case it blocks

Change-Id: I638bafc144604de5d71d0e578282ca35a799d6b7
diff --git a/VERSION b/VERSION
index 7c1886b..2cfabea 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.0.10
+0.0.11
diff --git a/internal/bbsim/devices/olt.go b/internal/bbsim/devices/olt.go
index 3cbb5fc..b16e405 100644
--- a/internal/bbsim/devices/olt.go
+++ b/internal/bbsim/devices/olt.go
@@ -222,7 +222,7 @@
 	// terminate the OLT's processOltMessages go routine
 	close(o.channel)
 	// terminate the OLT's processNniPacketIns go routine
-	o.nniHandle.Close()
+	go o.nniHandle.Close()
 	close(o.nniPktInChannel)
 
 	for i := range olt.Pons {