This change introduces new config options
`proxy_enabled` and `proxy_url`
that replace `socks5_*`.
Tested with deltachat-repl
by starting it with
`cargo run --locked -p deltachat-repl -- deltachat-db` and running
```
> set proxy_enabled 1
> set proxy_url ss://...
> setqr dcaccount:https://chatmail.example.org/new
> configure
```
This change replaces
usage of `reqwest` and `hyper-util`
with custom connection establishment code
so it is done in the same way
as for IMAP and SMTP connections.
This way we control HTTP, IMAP and SMTP
connection establishment
and schedule connection attempts
to resolved IP addresses
in the same way for all 3 protocols.
Before the fix HTTP client
had no connection timeout,
so it only had a chance
to test one IPv6 and one IPv4
address if the first addresses timed out.
Now it can test at least 4 addresses
of each family and more if some addresses
refuse connection rather than time out.
we're always checking the configuration encrypted.
saying it is 'preferred' encrypted is misleading,
therfore, just remove it.
i do not think, it is worth saying that we do not query 'http',
this is clear from the source code.
moreover, fix two typos.
This certificate does not exist on older Android phones.
It is already added manually for IMAP and SMTP,
this commit adds the same certificate for HTTP requests.
