Don't process detach and close as priority netmgr events

The detach (and possibly close) netmgr events can cause additional
callbacks to be called when under exclusive mode.  The detach can
trigger next queued TCP query to be processed and close will call
configured close callback.

Move the detach and close netmgr events from the priority queue to the
normal queue as the detaching and closing the sockets can wait for the
exclusive mode to be over.

lib/isc/netmgr/netmgr-int.h

@@ -329,6 +329,9 @@ typedef enum isc__netievent_type {
 	netievent_readcb,
 	netievent_sendcb,
 
+	netievent_detach,
+	netievent_close,
+
 	netievent_task,
 	netievent_privilegedtask,
 
@@ -352,8 +355,6 @@ typedef enum isc__netievent_type {
 	netievent_sockstop, /* for multilayer sockets */
 
 	netievent_resume,
-	netievent_detach,
-	netievent_close,
 } isc__netievent_type;
 
 typedef union {