Github integration issues

I'm using IDEA Community edition and I'm behind corporate firewall. I have SSH-tunnel to my rented VPS running PRIVOXY so I have both Socks (SSH -D) and HTTP (SSH -L) proxy options.

I can visit http://api.github.com/ via browser (FF) using any Socks/Http proxy. Unfortunally I have a set of problems trying to use IDEA:

1) IDEA can't fetch list of repositories from Github over SOCKS (SSH -D) proxy at all (works for HTTP proxy):

=================================

2018-08-24 13:56:16,458 [  45853]   INFO - .http.impl.execchain.RetryExec - I/O exception (org.apache.http.NoHttpResponseException) caught when processing request to {tls}->http://127.0.0.1:1081->https://api.github.com:443: The target server failed to respond
2018-08-24 13:56:16,458 [  45853]   INFO - .http.impl.execchain.RetryExec - Retrying request to {tls}->http://127.0.0.1:1081->https://api.github.com:443
2018-08-24 13:56:16,459 [  45854]   INFO - .http.impl.execchain.RetryExec - I/O exception (org.apache.http.NoHttpResponseException) caught when processing request to {tls}->http://127.0.0.1:1081->https://api.github.com:443: The target server failed to respond
2018-08-24 13:56:16,459 [  45854]   INFO - .http.impl.execchain.RetryExec - Retrying request to {tls}->http://127.0.0.1:1081->https://api.github.com:443
2018-08-24 13:56:16,460 [  45855]   INFO - .http.impl.execchain.RetryExec - I/O exception (org.apache.http.NoHttpResponseException) caught when processing request to {tls}->http://127.0.0.1:1081->https://api.github.com:443: The target server failed to respond
2018-08-24 13:56:16,460 [  45855]   INFO - .http.impl.execchain.RetryExec - Retrying request to {tls}->http://127.0.0.1:1081->https://api.github.com:443

=================================

2) Can't copy repository from Git at all (

=================================

14:04    Clone failed: unable to access 'https://github.com/dimzon/kpi-java-client.git/': Failed to connect to github.com port 443: Connection refused

=================================