Update NLA TimeGate endpoint

[ibnesayeed]

TimeGate endpoint has changed in NLA, the config file needs to be update accordingly.

$ curl -IL https://web.archive.org.au/awa/http://example.org/
HTTP/2 307 
server: nginx
date: Sat, 14 Mar 2020 14:56:01 GMT
content-length: 0
location: https://web.archive.org.au/awa/20190924232650/http://example.org/
link: <http://example.org/>; rel="original", <https://web.archive.org.au/awa/http://example.org/>; rel="timegate", <https://web.archive.org.au/awa/timemap/link/http://example.org/>; rel="timemap"; type="application/link-format", <https://web.archive.org.au/awa/20190924232650mp_/http://example.org/>; rel="memento"; datetime="Tue, 24 Sep 2019 23:26:50 GMT"
vary: accept-datetime