Merge pull request #3573 from ethcore/no-bg-download

CLI option to disable ancient block downloading

ethcore/src/blockchain/blockchain.rs

@@ -140,7 +140,7 @@ pub trait BlockProvider {
 	fn blocks_with_bloom(&self, bloom: &H2048, from_block: BlockNumber, to_block: BlockNumber) -> Vec<BlockNumber>;
 
 	/// Returns logs matching given filter.
-	fn logs<F>(&self, mut blocks: Vec<BlockNumber>, matches: F, limit: Option<usize>) -> Vec<LocalizedLogEntry>
+	fn logs<F>(&self, blocks: Vec<BlockNumber>, matches: F, limit: Option<usize>) -> Vec<LocalizedLogEntry>
 		where F: Fn(&LogEntry) -> bool, Self: Sized;
 }