Remove migration code. (#5291)

* Remove migration code.

* Fix cargo

* Bump spec version

substrate/frame/session/src/historical.rs

@@ -67,25 +67,7 @@ decl_storage! {
 }
 
 decl_module! {
-	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
-		fn on_initialize(_n: T::BlockNumber) {
-			CachedObsolete::<T>::remove_all();
-		}
-		fn on_runtime_upgrade() {
-			migration::migrate::<T>();
-		}
-	}
-}
-
-mod migration {
-	use super::*;
-	pub fn migrate<T: Trait>() {
-		if let Some((begin, end)) = StoredRange::get() {
-			for i in begin..end {
-				HistoricalSessions::<T>::migrate_key_from_blake(i);
-			}
-		}
-	}
+	pub struct Module<T: Trait> for enum Call where origin: T::Origin {}
 }
 
 impl<T: Trait> Module<T> {

substrate/frame/session/src/lib.rs

@@ -109,7 +109,6 @@ use frame_support::{ensure, decl_module, decl_event, decl_storage, decl_error, C
 use frame_support::{traits::{Get, FindAuthor, ValidatorRegistration}, Parameter};
 use frame_support::dispatch::{self, DispatchResult, DispatchError};
 use frame_system::{self as system, ensure_signed};
-use frame_support::traits::MigrateAccount;
 
 #[cfg(test)]
 mod mock;
@@ -504,18 +503,6 @@ decl_module! {
 	}
 }
 
-impl<T: Trait> MigrateAccount<T::AccountId> for Module<T> {
-	fn migrate_account(a: &T::AccountId) {
-		if let Some(v) = T::ValidatorIdOf::convert(a.clone()) {
-			if let Some(keys) = NextKeys::<T>::migrate_key_from_blake(v) {
-				for id in T::Keys::key_ids() {
-					KeyOwner::<T>::migrate_key_from_blake((*id, keys.get_raw(*id)));
-				}
-			}
-		}
-	}
-}
-
 impl<T: Trait> Module<T> {
 	/// Move on to next session. Register new validator set and session keys. Changes
 	/// to the validator set have a session of delay to take effect. This allows for

substrate/frame/session/src/mock.rs

@@ -179,7 +179,7 @@ impl frame_system::Trait for Test {
 	type Version = ();
 	type ModuleToIndex = ();
 	type AccountData = ();
-	type MigrateAccount = (); type OnNewAccount = ();
+	type OnNewAccount = ();
 	type OnKilledAccount = ();
 }