When `trusted-node-url` is used nimbus ExecStart will be different and will use `trustedNodeSync` parameter.

Also got `nimbus-eth2` working with the changes from the `nix-community/ethereum.nix` repo

…r loading secrets

* config(modules/nimbus-eth2): Don't define custom user for the service, but rely on the DynamicUser
* config(modules/lib.nix): Add `ProcSubset` to baseServiceConfig
* config(modules/erigon): Refactor systemd config to use LoadCredential

…b/nbc.sqlite3` exists

Skip trustedNodeSync if it already exists.

…f not compatible

In newer versions of `nixpkgs-unstable` the `nim` package points to
`2.0.0`. A new package `nim1` has been added for backwards
compatibility.

Since we can't be sure with what version of nixpkgs-unstable we will be
instantiated fallback to `nim` if `nim1` does not exist.

Pruning fails and errors are thrown in the most recent version (1.13.10) when `ProcSubset` is set to `pid`, as in lib.nix

…forms

…all)

`ProcSubset=pid` causes various problems for both nimbus and geth
(and possibly other services), so it's better to revert that change.

not all arguments are passed into the module