ONOS-3411 Disconnect switches and stop stat collectors when openflow-base is being deactivated

Change-Id: I9a1b5fbb60a9e7135cd586fe717c18f83e3d864d
diff --git a/protocols/openflow/api/src/main/java/org/onosproject/openflow/controller/driver/AbstractOpenFlowSwitch.java b/protocols/openflow/api/src/main/java/org/onosproject/openflow/controller/driver/AbstractOpenFlowSwitch.java
index c717419..08444b1 100644
--- a/protocols/openflow/api/src/main/java/org/onosproject/openflow/controller/driver/AbstractOpenFlowSwitch.java
+++ b/protocols/openflow/api/src/main/java/org/onosproject/openflow/controller/driver/AbstractOpenFlowSwitch.java
@@ -98,6 +98,7 @@
 
     @Override
     public final void disconnectSwitch() {
+        setConnected(false);
         this.channel.close();
     }