fix compile with new compiler - dead code (#4530)

* make compiler happy

* node side compile warning quiet

* ffs

* malus: remove unused keystore

polkadot/utils/staking-miner/src/main.rs

@@ -319,10 +319,12 @@ struct MonitorConfig {
 #[derive(Debug, Clone, StructOpt)]
 struct EmergencySolutionConfig {
 	/// The block hash at which scraping happens. If none is provided, the latest head is used.
+	#[allow(dead_code)]
 	#[structopt(long)]
 	at: Option<Hash>,
 
 	/// The solver algorithm to use.
+	#[allow(dead_code)]
 	#[structopt(subcommand)]
 	solver: Solvers,