Fix Vulnerability -- Apache Web Server ETag Header Information Disclosure

To fix this bug, we have to simply update the apache configuration http.conf file.

To remove the complete Etag info then use FileETag None
To hide only Inode info then use FileETag -INode

By removing the ETag header, you disable caches and browsers from being able to validate files, so they are forced to rely on your Cache-Control and Expires header.