Use an unaltered config.js file

Make all the necessary changes outside, setting the bosh URL
in this case.

web/rootfs/defaults/config.js

@@ -38,7 +38,7 @@ var config = {
     },
 
     // BOSH URL. FIXME: use XEP-0156 to discover it.
-    bosh: '/http-bind',
+    bosh: '//jitsi-meet.example.com/http-bind',
 
     // The name of client node advertised in XEP-0115 'c' stanza
     clientNode: 'http://jitsi.org/jitsimeet',

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

@@ -22,5 +22,8 @@ fi
 
 if [[ ! -f /config/config.js ]]; then
     cp /defaults/config.js /config/config.js
-	sed -i "s/jitsi-meet.example.com/$XMPP_DOMAIN/g" /config/config.js
+    sed -i \
+        -e "s#jitsi-meet.example.com#$XMPP_DOMAIN#g" \
+        -e "s#bosh:.*#bosh: '/http-bind',#" \
+        /config/config.js
 fi