[11100] Avoid send SMSG_DISMOUNT for non aura source mount state.

This fix problem with lost mount show at multi-node taxi path.

Thanks to blueboy for research problem.

src/game/MiscHandler.cpp

@@ -1469,7 +1469,7 @@ void WorldSession::HandleCancelMountAuraOpcode( WorldPacket & /*recv_data*/ )
         return;
     }
 
-    _player->Unmount();
+    _player->Unmount(_player->HasAuraType(SPELL_AURA_MOUNTED));
     _player->RemoveSpellsCausingAura(SPELL_AURA_MOUNTED);
 }