fix: invalid forced sync peer now returns configerror

[StriderDM]

Description

Fixed bug which returned an UnknownError instead of a ConfigError for invalid force sync peers.
Remove double print of error.

Output:

Running `target\debug\tari_base_node.exe`
Initializing logging according to "C:\\Users\\DMStrider\\.tari\\config\\log4rs_base_node.yml"
Please check your force sync peers configuration
ConfigError("Invalid force sync peer: Invalid public key string")
14:43 ERROR Exiting with code (101): ConfigError("Invalid force sync peer: Invalid public key string")

Motivation and Context

Previously an UnknownError was reported for invalid force sync peers

How Has This Been Tested?

Configuration with invalid force_sync_peers.