apache2-mpm-worker deprecated, cannot install Concerto. Can package dependencies please be updated?

[Howard Dingman]

Clean install new Ubuntu 15.10 LAMP server with all updates.
New version apache2 and apache2-bin installed.
I added the concerto PPA, and ran apt-get update.
Then I tried to install concerto-full. Result -

<user>@<servername>:~$ sudo apt-get install concerto-full
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 concerto-full : Depends: apache2-mpm-worker but it is not installable or
                          apache2-mpm-prefork but it is not installable
E: Unable to correct problems, you have held broken packages.
<user>@<servername>:~$ sudo apt-get install apache2-mpm-worker
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package apache2-mpm-worker 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:
  apache2-bin

E: Package 'apache2-mpm-worker' has no installation candidate
<user>@<servername>:~$ sudo apt-get install apache2-mpm-prefork
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package apache2-mpm-prefork 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:
  apache2-bin

E: Package 'apache2-mpm-prefork' has no installation candidate
<user>@<servername>:~ $ sudo apt-get install apache2-bin
Reading package lists... Done
Building dependency tree
Reading state information... Done
apache2-bin is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
<user>@<servername>:~ $