BUG/MINOR: proxy: make soft_stop() also close FDs in LI_PAUSED state

The proxies' soft_stop() function closes the FDs in all opened states
except LI_PAUSED. This means that a transient error on a listener might
cause it to turn back to the READY state if it happens exactly when a
reload signal is received.

This must be backported to all supported versions.
diff --git a/src/proxy.c b/src/proxy.c
index ebc6415..1724766 100644
--- a/src/proxy.c
+++ b/src/proxy.c
@@ -1134,10 +1134,10 @@
 		if (p->state == PR_STSTOPPED &&
 		    !LIST_ISEMPTY(&p->conf.listeners) &&
 		    LIST_ELEM(p->conf.listeners.n,
-		    struct listener *, by_fe)->state >= LI_ZOMBIE) {
+		    struct listener *, by_fe)->state > LI_ASSIGNED) {
 			struct listener *l;
 			list_for_each_entry(l, &p->conf.listeners, by_fe) {
-				if (l->state >= LI_ZOMBIE)
+				if (l->state > LI_ASSIGNED)
 					close(l->fd);
 				l->state = LI_INIT;
 			}