Decrease default --out-peers from 25 to 15 (#12434)

Co-authored-by: Bastian Köcher <git@kchr.de>

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

@@ -82,12 +82,13 @@ pub struct NetworkParams {
 	pub allow_private_ipv4: bool,
 
 	/// Specify the number of outgoing connections we're trying to maintain.
-	#[arg(long, value_name = "COUNT", default_value_t = 25)]
+	#[arg(long, value_name = "COUNT", default_value_t = 15)]
 	pub out_peers: u32,
 
 	/// Maximum number of inbound full nodes peers.
 	#[arg(long, value_name = "COUNT", default_value_t = 25)]
 	pub in_peers: u32,
+
 	/// Maximum number of inbound light nodes peers.
 	#[arg(long, value_name = "COUNT", default_value_t = 100)]
 	pub in_peers_light: u32,