Make network_config_path an Option (#5661)

* Make network_config_path an Option

* Fix network tests

* Use None as the network config path

* Fix cli

* Don't make PathBuf an Option in a cli context

substrate/client/cli/src/params/network_params.rs

@@ -96,7 +96,7 @@ impl NetworkParams {
 		&self,
 		chain_spec: &Box<dyn ChainSpec>,
 		is_dev: bool,
-		net_config_path: &PathBuf,
+		net_config_path: Option<PathBuf>,
 		client_id: &str,
 		node_name: &str,
 		node_key: NodeKeyConfig,
@@ -121,7 +121,7 @@ impl NetworkParams {
 
 		NetworkConfiguration {
 			boot_nodes,
-			net_config_path: net_config_path.clone(),
+			net_config_path,
 			reserved_nodes: self.reserved_nodes.clone(),
 			non_reserved_mode: if self.reserved_only {
 				NonReservedPeerMode::Deny