Fix (optional) initial fetch of eip-service.json
Currently menshen can be started with a pre-fetched eip-service.json file or with a remote URL from where the eip-service.json can be fetched. The 2. option was broken after Riseup revamped their backend.
The reason for it is that when fetching eip-service.json the http client doesn't use the provider's custom CA cert for a request although it's an 'api' endpoint. The issue surfaced after fixing the eip-serivce url in jnk: https://www.0xacab.org/leap/jnk/-/merge_requests/5/diffs