fix: use default server list for providers that don't have one

There are providers in the provider database
that do not have servers specified.
For such providers default list should be tried
just like when configuring unknown providers.

src/configure.rs

@@ -11,7 +11,7 @@
 
 mod auto_mozilla;
 mod auto_outlook;
-mod server_params;
+pub(crate) mod server_params;
 
 use anyhow::{bail, ensure, Context as _, Result};
 use auto_mozilla::moz_autoconfigure;