Fix 'Add Page' in the Channel Manager when a campaign is running

@Override
    public Map<String, XPageLayout> getXPageLayouts(final String channelId) {
      
        for (HstModel hstModel : hstModelRegistry.getModels().values()) {

            HippoWebappContext context = HippoWebappContextRegistry.get().getContext(hstModel.getVirtualHosts().getContextPath());

            if (context == null) {
                continue;
            }
            if (CMS_OR_PLATFORM.contains(context.getType())) {
                continue;
            }

            final VirtualHosts virtualHosts = hstModel.getVirtualHosts();

            // just find the first Mount which have a matching channel id, and create the XPageLayout from that
            // channel (it doesn't matter through which hostgroup the channel is found

            // note that 'channelId' can be for a branch as well!

            final Optional<Map<String, HstComponentConfiguration>> xPageLayoutComponents = virtualHosts.getHostGroupNames().stream()
                    .filter(hostgroupName -> virtualHosts.getChannelById(hostgroupName, channelId) != null)
                    .flatMap(hostgroupName -> virtualHosts.getMountsByHostGroup(hostgroupName).stream()).collect(Collectors.toList())
                    .stream()
                    .filter(mount -> mount.getChannel() != null && channelId.equals(mount.getChannel().getId()))
                    .map(mount -> mount.getHstSite().getComponentsConfiguration().getXPages())
                    .findFirst();

            if (!xPageLayoutComponents.isPresent()) {
                log.info("Cannot find any XPageLayouts for channel '{}'", channelId);
                continue;
            } else {
                return getXPageLayouts(xPageLayoutComponents.get());
            }
        }

        return Collections.emptyMap();
    }