Apache 2.4 is sufficiently different from earlier releases that a new tag apache-2.4 has recently been created for it. There are a number of questions that have already been asked about Apache 2.4 which have been tagged apache-2.2, these need to be cleaned up.
If you have some spare time you can use this querythis query to identify questions that may need a retag and retag them. It's likely that not all of the questions will need retaging but this will get us close.