Define ss58 prefix inside the runtime (#7810)

* Add SS58Prefix type to the frame_system config trait

* Remove unused chain_id runtime interface

substrate/bin/node-template/runtime/src/lib.rs

@@ -136,6 +136,7 @@ parameter_types! {
 		::with_sensible_defaults(2 * WEIGHT_PER_SECOND, NORMAL_DISPATCH_RATIO);
 	pub BlockLength: frame_system::limits::BlockLength = frame_system::limits::BlockLength
 		::max_with_normal_ratio(5 * 1024 * 1024, NORMAL_DISPATCH_RATIO);
+	pub const SS58Prefix: u8 = 42;
 }
 
 // Configure FRAME pallets to include in runtime.
@@ -185,6 +186,8 @@ impl frame_system::Config for Runtime {
 	type AccountData = pallet_balances::AccountData<Balance>;
 	/// Weight information for the extrinsics of this pallet.
 	type SystemWeightInfo = ();
+	/// This is used as an identifier of the chain. 42 is the generic substrate prefix.
+	type SS58Prefix = SS58Prefix;
 }
 
 impl pallet_aura::Config for Runtime {