Revert "Build block without checking signatures (#4916)" (#5159)

* Revert "Build block without checking signatures (#4916)"

This reverts commit e50f610907.

* Some further clean ups

substrate/frame/transaction-payment/src/lib.rs

@@ -258,7 +258,7 @@ mod tests {
 	use sp_core::H256;
 	use sp_runtime::{
 		testing::{Header, TestXt},
-		traits::{BlakeTwo256, Extrinsic, IdentityLookup},
+		traits::{BlakeTwo256, IdentityLookup},
 		Perbill,
 	};
 	use std::cell::RefCell;
@@ -535,7 +535,7 @@ mod tests {
 		let call = Call::Balances(BalancesCall::transfer(2, 69));
 		let origin = 111111;
 		let extra = ();
-		let xt = TestXt::new(call, Some((origin, extra))).unwrap();
+		let xt = TestXt::new(call, Some((origin, extra)));
 		let info  = xt.get_dispatch_info();
 		let ext = xt.encode();
 		let len = ext.len() as u32;