log with the failed item description, not with next try

The failure handling frequently changes URI & Description of the failed
item to try a slightly different combination which might work, but the
logging of the failure happens only afterwards as the same failure
handling decides if this is a critical error or not so we need a backup
here instead of potentially new content.

A purely cosmetic issue, but can still be confusing for humans.

apt-pkg/acquire-worker.cc

@@ -464,6 +464,7 @@ bool pkgAcquire::Worker::RunMessages()
 	       }
 	       else
 	       {
+		  auto SavedDesc = Owner->GetItemDesc();
 		  if (isDoomedItem(Owner) == false)
 		  {
 		     if (Message.find("\nFailReason:") == std::string::npos)
@@ -476,7 +477,7 @@ bool pkgAcquire::Worker::RunMessages()
 		     Owner->Failed(Message,Config);
 		  }
 		  if (Log != nullptr)
-		     Log->Fail(Owner->GetItemDesc());
+		     Log->Fail(SavedDesc);
 	       }
 	    }
 	    ItemDone();
@@ -524,11 +525,11 @@ bool pkgAcquire::Worker::RunMessages()
 		  Owner->Status = pkgAcquire::Item::StatAuthError;
 	       else if (errTransient)
 		  Owner->Status = pkgAcquire::Item::StatTransientNetworkError;
-
+	       auto SavedDesc = Owner->GetItemDesc();
 	       if (isDoomedItem(Owner) == false)
 		  Owner->Failed(Message,Config);
 	       if (Log != nullptr)
-		  Log->Fail(Owner->GetItemDesc());
+		  Log->Fail(SavedDesc);
 	    }
 	    ItemDone();