BUG #15780: Win10 PGS11 installer includes psAdmin3 LTS which does not support PGS11

The following bug has been logged on the website:

Bug reference: 15780
Logged by: W Dagnon
Email address: wdagnon(at)wfscorp(dot)com
PostgreSQL version: 11.2
Operating system: Windows 10
Description:

I downloaded the Windows installer for PostGreSQL 11 and got my admins to
run it.
I can use PSQL just fine.
I tried opening psAdmin3 LTS, installed with the package, and it throws a
slew of errors if I try connecting to my local PostGreSQL. The first one
is:

"Warning: The server you are connecting to is not a version that is
supported by this release of pgAdmin3 LTS by BigSQL. pgAdmin3 LTS by BigSQL
may not function as expected. Supported server versions are 8.4 to 9.5 and
10."

The local server shows up in the Object Browser pane with a red "X" over the
icon - but that disappears after connecting. When opening objects, it
throws multiple errors like "cannot find column usecreatedb" of "ERROR:
column 'proisagg' does not exist" ...