Use connection property for errors in message receiver.

SignalServiceKit/src/Messages/OWSMessageReceiver.m

@@ -380,8 +380,7 @@ NSString *const OWSMessageDecryptJobFinderExtensionGroup = @"OWSMessageProcessin
         OWSFailDebug(@"Could not parse proto.");
         // TODO: Add analytics.
 
-        [[OWSPrimaryStorage.sharedManager newDatabaseConnection]
-            readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
+        [self.dbConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
             TSErrorMessage *errorMessage = [TSErrorMessage corruptedMessageInUnknownThread];
             [SSKEnvironment.shared.notificationsManager notifyUserForThreadlessErrorMessage:errorMessage
                                                                                 transaction:transaction];