Ensure TSRecipient can be deserialized.

SignalServiceKit/src/Storage/TSRecipient.h

@@ -1,12 +1,14 @@
 //
-//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
 //
 
+#import "TSYapDatabaseObject.h"
+
 NS_ASSUME_NONNULL_BEGIN
 
 // Some lingering TSRecipient records in the wild causing crashes.
 // This is a stop gap until a proper cleanup happens.
-@interface TSRecipient : NSObject <NSCoding>
+@interface TSRecipient : TSYapDatabaseObject
 
 @end
 

SignalServiceKit/src/Storage/TSRecipient.m

@@ -8,14 +8,6 @@ NS_ASSUME_NONNULL_BEGIN
 
 @implementation TSRecipient
 
-- (void)encodeWithCoder:(nonnull NSCoder *)aCoder {
-    return;
-}
-
-- (nullable instancetype)initWithCoder:(nonnull NSCoder *)aDecoder {
-    return nil;
-}
-
 @end
 
 NS_ASSUME_NONNULL_END