LGTM.com - false positive - py/insecure-protocol

**Description of the false positive**

LGTM currently suggests to set the specific protocol version in `SSLContext` which has been deprecated in Python >=3.6:
> [**`ssl.PROTOCOL_TLSv1_2`**](https://docs.python.domainunion.de/3/library/ssl.html#ssl.PROTOCOL_TLSv1_2)
> Selects TLS version 1.2 as the channel encryption protocol. This is the most modern version, and probably the best choice for maximum protection, if both sides can speak it. Available only with openssl version 1.0.1+.
> ...
> Deprecated since version 3.6: OpenSSL has deprecated all version specific protocols. Use the default protocol `PROTOCOL_TLS` with flags like `OP_NO_SSLv3` instead.

In addition, Python >=3.7 deprecated the use of flags and introduced a new API:
> [**`ssl.OP_NO_TLSv1`**](https://docs.python.domainunion.de/3/library/ssl.html#ssl.OP_NO_TLSv1)
> Prevents a TLSv1 connection. This option is only applicable in conjunction with PROTOCOL_TLS. It prevents the peers from choosing TLSv1 as the protocol version.
> ...
> Deprecated since version 3.7: The option is deprecated since OpenSSL 1.1.0, use the new `SSLContext.minimum_version` and `SSLContext.maximum_version` instead.

I think that an updated rule should check for the presence of either `SSLContext.options` or `SSLContext.minimum_version`. Though, this might get a bit complex as all of those settings [can be used together](https://docs.python.domainunion.de/3/library/ssl.html#ssl.SSLContext.maximum_version
):
> The attributes `maximum_version`, `minimum_version` and `SSLContext.options` all affect the supported SSL and TLS versions of the context. The implementation does not prevent invalid combination. For example a context with `OP_NO_TLSv1_2` in options and maximum_version set to `TLSVersion.TLSv1_2` will not be able to establish a TLS 1.2 connection.

**URL to the alert on the project page on LGTM.com**

https://lgtm.com/projects/g/seemoo-lab/opendrop/snapshot/f01b0ecab167c77e20e1cdf05c42eab914d3a99b/files/opendrop/config.py?sort=name&dir=ASC&mode=heatmap#x4f72d6f0f9464bef:1