re-enable contrib/dlb proxy extension

$ curl -vLOs https://downloadmirror.intel.com/819078/dlb_linux_src_release_8.8.0.txz
* Host downloadmirror.intel.com:443 was resolved.
* IPv6: (none)
* IPv4: 52.85.193.78, 52.85.193.96, 52.85.193.100, 52.85.193.22
*   Trying 52.85.193.78:443...
* ALPN: curl offers h2,http/1.1
} [5 bytes data]
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
} [1583 bytes data]
* SSL Trust Anchors:
*   CAfile: /etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem
{ [5 bytes data]
* TLSv1.3 (IN), TLS handshake, Server hello (2):
{ [1210 bytes data]
* TLSv1.3 (IN), TLS change cipher, Change cipher spec (1):
{ [1 bytes data]
* TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
{ [19 bytes data]
* TLSv1.3 (IN), TLS handshake, Certificate (11):
{ [4878 bytes data]
* TLSv1.3 (IN), TLS handshake, CERT verify (15):
{ [264 bytes data]
* TLSv1.3 (IN), TLS handshake, Finished (20):
{ [36 bytes data]
* TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
} [1 bytes data]
* TLSv1.3 (OUT), TLS handshake, Finished (20):
} [36 bytes data]
* SSL connection using TLSv1.3 / TLS_AES_128_GCM_SHA256 / X25519MLKEM768 / RSASSA-PSS
* ALPN: server accepted h2
* Server certificate:
*   subject: C=US; ST=California; O=Intel Corporation; CN=downloadmirror.intel.com
*   start date: May  5 00:00:00 2026 GMT
*   expire date: Aug  3 23:59:59 2026 GMT
*   issuer: C=GB; O=Sectigo Limited; CN=Sectigo Public Server Authentication CA OV R36
*   Certificate level 0: Public key type RSA (2048/112 Bits/secBits), signed using sha256WithRSAEncryption
*   Certificate level 1: Public key type RSA (3072/128 Bits/secBits), signed using sha384WithRSAEncryption
*   Certificate level 2: Public key type RSA (4096/152 Bits/secBits), signed using sha384WithRSAEncryption
*   subjectAltName: "downloadmirror.intel.com" matches cert's "downloadmirror.intel.com"
* SSL certificate verified via OpenSSL.
* Established connection to downloadmirror.intel.com (52.85.193.78 port 443) from 192.168.1.157 port 36418 
* using HTTP/2
* [HTTP/2] [1] OPENED stream for https://downloadmirror.intel.com/819078/dlb_linux_src_release_8.8.0.txz
* [HTTP/2] [1] [:method: GET]
* [HTTP/2] [1] [:scheme: https]
* [HTTP/2] [1] [:authority: downloadmirror.intel.com]
* [HTTP/2] [1] [:path: /819078/dlb_linux_src_release_8.8.0.txz]
* [HTTP/2] [1] [user-agent: curl/8.18.0]
* [HTTP/2] [1] [accept: */*]
} [5 bytes data]
> GET /819078/dlb_linux_src_release_8.8.0.txz HTTP/2
> Host: downloadmirror.intel.com
> User-Agent: curl/8.18.0
> Accept: */*
> 
* Request completely sent off
} [5 bytes data]
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
{ [157 bytes data]
< HTTP/2 202 
< server: CloudFront
< date: Fri, 05 Jun 2026 20:01:07 GMT
< content-length: 0
< x-amzn-waf-action: challenge
< cache-control: no-store, max-age=0
< content-type: text/html; charset=UTF-8
< access-control-allow-origin: *
< access-control-max-age: 86400
< access-control-allow-methods: OPTIONS,GET,POST
< access-control-expose-headers: x-amzn-waf-action
< x-cache: Error from cloudfront
< via: 1.1 0145ea6cf3813022e500cf46dfa7f256.cloudfront.net (CloudFront)
< x-amz-cf-pop: IAD55-P10
< x-amz-cf-id: W9OlSGyTSAVeomP1pEPmCzLhX6SFjIQQvLrgWJWcRVBY3Y8fTp7ZTg==
< 
{ [0 bytes data]
* Connection #0 to host downloadmirror.intel.com:443 left intact