cert within prosody config

src/freedombone-app-jitsi

     if [ -f /etc/ssl/certs/${JITSI_DOMAIN_NAME}.pem ]; then
         sed -i "s|.crt|.pem|g" $jitsi_nginx_site
         sed -i "s|.crt|.pem|g" /etc/prosody/conf.d/${JITSI_DOMAIN_NAME}.cfg.lua
+        sed -i "s|certificate =.*|certificate = \"${JITSI_DOMAIN_NAME}.pem\"|g" /etc/prosody/conf.avail/${JITSI_DOMAIN_NAME}.cfg.lua
     fi
     sed -i "s|.conf.crt|.crt|g" /etc/nginx/sites-available/${JITSI_DOMAIN_NAME}.conf
     sed -i "s|.conf.pem|.pem|g" /etc/nginx/sites-available/${JITSI_DOMAIN_NAME}.conf