core: don't block startup on assumed connections

If we are assuming a connection at startup, the NMManager:startup
state doesn't need to wait for that activation to complete, since the
underlying device isn't going to change its configuration as a result
of it.

(In particular, NM considers virbr0 to be stalled at
NM_DEVICE_STATE_IP_CONFIG when it assumes it, since if it has no real
slaves, it won't yet have carrier. But this shouldn't block startup.)

src/nm-active-connection.c

@@ -401,9 +401,11 @@ nm_active_connection_set_device (NMActiveConnection *self, NMDevice *device)
 		g_signal_connect (device, "notify::master",
 		                  G_CALLBACK (device_master_changed), self);
 
+		if (!priv->assumed) {
 			priv->pending_activation_id = g_strdup_printf ("activation::%p", (void *)self);
 			nm_device_add_pending_action (device, priv->pending_activation_id);
 		}
+	}
 	return TRUE;
 }
 
@@ -540,6 +542,11 @@ nm_active_connection_set_assumed (NMActiveConnection *self, gboolean assumed)
 
 	g_return_if_fail (priv->assumed == FALSE);
 	priv->assumed = assumed;
+
+	if (priv->pending_activation_id) {
+		nm_device_remove_pending_action (priv->device, priv->pending_activation_id);
+		g_clear_pointer (&priv->pending_activation_id, g_free);
+	}
 }
 
 gboolean