Update nginx.conf

[impedator]

removed nginx listening on IPv6.

[j0k3r]

Why?
Because #385

[impedator]

adding IPv6 listen in IPv4-only environment causing problem with nginx startup:

wallabag-wallabag-1 | --- ------------------------ ------------------
wallabag-wallabag-1 | Bundle Method / Error
wallabag-wallabag-1 | --- ------------------------ ------------------
wallabag-wallabag-1 | Γ£ö NelmioApiDocBundle relative symlink
wallabag-wallabag-1 | Γ£ö CraueConfigBundle relative symlink
wallabag-wallabag-1 | Γ£ö BabDevPagerfantaBundle relative symlink
wallabag-wallabag-1 | Γ£ö FOSJsRoutingBundle relative symlink
wallabag-wallabag-1 | --- ------------------------ ------------------
wallabag-wallabag-1 |
wallabag-wallabag-1 | [OK] All assets were successfully installed.
wallabag-wallabag-1 |
wallabag-wallabag-1 | wallabag is ready!
wallabag-wallabag-1 | 2025/03/14 11:25:21 [emerg] 57#57: socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | nginx: [emerg] socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | 2025/03/14 11:25:22 [emerg] 61#61: socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | nginx: [emerg] socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | 2025/03/14 11:25:23 [emerg] 63#63: socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | nginx: [emerg] socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | 2025/03/14 11:25:24 [emerg] 65#65: socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | nginx: [emerg] socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | 2025/03/14 11:25:25 [emerg] 73#73: socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | nginx: [emerg] socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | 2025/03/14 11:25:26 [emerg] 75#75: socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | nginx: [emerg] socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | 2025/03/14 11:25:27 [emerg] 77#77: socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | nginx: [emerg] socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | 2025/03/14 11:25:29 [emerg] 79#79: socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | nginx: [emerg] socket() [::]:80 failed (97: Address family not supported by protocol)
wallabag-wallabag-1 | 2025/03/14 11:25:30 [emerg] 81#81: socket() [::]:80 failed (97: Address family not supported by protocol)

this is also related to: #422