You can restore the default Apache configuration without reinstalling Apache.
The folders with Apache configuration files have read-only .default files that store default Apache settings. You can run a command in Terminal that replaces all changed configuration files with these default files.
For information about important Apache configuration files, see the ReadMe.txt file in /Library/Server/Web/Config/apache2/.
Open Terminal.
Enter the following command:
$ sudo serveradmin command web:command=restoreFactorySettings
When you see web = _empty_dictionary
, you’ve successfully restored factory settings for web service.