Reading package lists... Done
Building dependency tree
Reading state information... Done
Package apache2 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
However the following packages replace it:
  libapache2-mpm-itk:i386 libapache2-mpm-itk

E: Package 'apache2' has no installation candidate