Don't print an object in the debug log

There is no stringify function on RT::Transaction, so this is causing
log entries like:

[4044261] [Sat Nov 11 11:30:40 2023] [debug]: Calling SetRecipientDigests for transaction RT::Transaction=HASH(0x563feb2b4fb0), id 44 (lib/RT/Action/SendEmail.pm:693)

Let's not have the RT::Transaction=HASH(0x563feb2b4fb0) in there.

Author: puck

lib/RT/Action/SendEmail.pm

@@ -693,7 +693,7 @@ sub SetRTSpecialHeaders {
 
 sub DeferDigestRecipients {
     my $self = shift;
-    $RT::Logger->debug( "Calling SetRecipientDigests for transaction " . $self->TransactionObj . ", id " . $self->TransactionObj->id );
+    $RT::Logger->debug( "Calling SetRecipientDigests for transaction id " . $self->TransactionObj->id );
 
     # The digest attribute will be an array of notifications that need to
     # be sent for this transaction.  The array will have the following