Panic occurs for using Unix sockets

[lamchakchan]

Description

When trying unix socket for the remote-control interface, the exporter has no way to be configured to input the unix socket address without a panic. Looks the the use of Parse() from net/url fails to recognize the scheme for a target of unix:///var/run/unbound/control.sock.

Unbound Configuration

server:
    ...
remote-control:
    control-enable: yes
    control-use-cert: no
    control-interface: "/var/run/unbound/control.sock"

Command

unbound-exporter -unbound.host unix:///var/run/unbound/control.sock

Error

level=info ts=2023-10-30T21:31:55.062Z caller=unbound_exporter.go:509 Startingunbound_exporter=(MISSING)
panic: open /etc/unbound/unbound_server.pem: no such file or directory

goroutine 1 [running]:
main.main()