BUG/MEDIUM: h1: Destroy a connection after detach if it has no owner.

Destroy the connection while detaching, even if it has keep alive, if it has
no owner, or nobody else will be able to do so.
diff --git a/src/mux_h1.c b/src/mux_h1.c
index b01e5d7..ff54adc 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -1722,7 +1722,7 @@
 	h1c = h1s->h1c;
 	h1s->cs = NULL;
 
-	if (conn_is_back(h1c->conn) && (h1s->flags & H1S_F_WANT_KAL)) {
+	if (conn_is_back(h1c->conn) && (h1s->flags & H1S_F_WANT_KAL) && h1c->conn->owner) {
 		/* Never ever allow to reuse a connection from a non-reuse backend */
 		if (h1c->conn && (h1c->px->options & PR_O_REUSE_MASK) == PR_O_REUSE_NEVR)
 			h1c->conn->flags |= CO_FL_PRIVATE;
@@ -1746,7 +1746,7 @@
 
 	/* We don't want to close right now unless the connection is in error */
 	if ((h1c->flags & (H1C_F_CS_ERROR|H1C_F_CS_SHUTW)) ||
-	    (h1c->conn->flags & CO_FL_ERROR))
+	    (h1c->conn->flags & CO_FL_ERROR) || !h1c->conn->owner)
 		h1_release(h1c->conn);
 	else
 		tasklet_wakeup(h1c->wait_event.task);