Privacy issue: Accesses to external sites from private installation #1010

A private installation through docker-compose accesses following external sites by default:

1. mist.io
2. js.stripe.com, m.stripe.network
3. gravatar.com
4. io.wp.com

This allows those sites to spy the installation existence through the http Referer, and for Stripe through the URL as well, and additionally to actually access through JS all HTML content on the page (including private keys and passwords). It renders the mist.io vulnerable to a potential breach and/or vulnerabilities of stripe.com.

I am reporting this privacy issue and security issue publicly, since it is a very low risk vulnerability (as it basically requires a breach in Stripe.com to become exploitable), and mainly a privacy issue, which is deserving transparency.

Here a few suggestions to remove any external accesses from mist.io webpages:

1. and 4. : mist.io and io.wp.com are just for fetching the default user icon, so can easily be changed to a local version of the icon.

2. gravatar.com tries to fetch the user picture, but this feature should be off by default.

3. stripe.com is fetched on all pages, instead of only the payments page when the user actually wants to upgrade. However, it is considered bad practice to have the payment page hosted elsewhere than on your own domain. This is against normal rules can give a bad reputation to your own payment provider (e.g. if your software is used on sites with content prohibited by the payment provider.

Here the URLs accessed (seen through browser debug/network) e.g. on the Teams page:

1. https://mist.io/ui/assets/user.png
2. https://js.stripe.com/v2/
3. https://js.stripe.com/v2/channel.html?stripe_xdm_e=http%3A%2F%2F10.0.0.2&stripe_xdm_c=default89171&stripe_xdm_p=1#__stripe_transport__
4. https://js.stripe.com/v2/m/outer.html#referrer=&title=Mist%20CE&url=http%3A%2F%2F10.0.0.2%2Fteams&muid=6d46154b-c7e9-4608-840d-505f10cb6eaa6e2f49&sid=eaf14818-6e6b-4b0d-b27e-016af103605b50ed41&version=6&preview=false&
5. https://js.stripe.com/v2/
6. https://m.stripe.network/inner.html#referrer=&title=Mist%20CE&url=http%3A%2F%2F10.0.0.2%2Fteams&muid=6d46154b-c7e9-4608-840d-505f10cb6eaa6e2f49&sid=eaf14818-6e6b-4b0d-b27e-016af103605b50ed41&version=6&preview=false&
7. https://www.gravatar.com/avatar/b67b5926b459623d2f0e0b389059f072.jpg?s=40&d=https://mist.io/ui/assets/user.png
8. https://m.stripe.network/out-4.5.35.js
9. https://m.stripe.com/6
10. https://i0.wp.com/mist.io/ui/assets/user.png?ssl=1
11. https://m.stripe.com/6
12. https://m.stripe.com/6
13. https://m.stripe.com/6