web: revert using PUBLIC_URL for BOSH URL

This partially reverts
5e6faced4f

It was unnecessary, and created lot of trouble.

web/rootfs/etc/cont-init.d/10-config

@@ -73,7 +73,7 @@ if [[ ! -f /config/config.js ]]; then
     cp /defaults/config.js /config/config.js
     sed -i \
         -e "s#jitsi-meet.example.com#$XMPP_DOMAIN#g" \
-        -e "s#bosh:.*#bosh: '${PUBLIC_URL}/http-bind',#" \
+        -e "s#bosh:.*#bosh: '/http-bind',#" \
         -e "s#muc:.*#muc: '${XMPP_MUC_DOMAIN}',#" \
         -e "s#// focusUserJid:.*#focusUserJid: '${JICOFO_AUTH_USER}@${XMPP_AUTH_DOMAIN}',#" \
         /config/config.js