Updating mate-screensaver from disco to bionic

What is the easiest way to update my mate-screensaver from 1.20.0-1 (bionic) to 1.20.3-3 (disco)? I'm running Ubuntu MATE 18.04 and the current version has a nasty bug of opening the screen sometimes without the password when attaching external display.

I tried pinning the package from disco but got stuck with dependency problems.

Added this to /etc/apt/sources.list
deb http://archive.ubuntu.com/ubuntu disco main restricted universe multiverse

Then pinned mate-screensaver and some dependencies:

$ cat /etc/apt/preferences.d/screensaver.pref
Package: mate-screensaver
Pin: release n=disco
Pin-Priority: 500

Package: librda0
Pin: release n=disco
Pin-Priority: 500

Package: mate-screensaver-common
Pin: release n=disco
Pin-Priority: 500

Package: librda-common
Pin release n=disco
Pin-Priority: 500

Package: *
Pin: release n=disco
Pin-Priority: -10

mate-screensaver needed mate-screensaver-common and librd0, but librda0 also need librda-common which is not available. I ended up in here:

$ apt policy mate-screensaver
mate-screensaver:
Installed: 1.20.0-1
Candidate: 1.20.3-3
Version table:
1.20.3-3 500
-10 Index of /ubuntu disco/universe amd64 Packages
*** 1.20.0-1 500
500 Index of /ubuntu bionic/universe amd64 Packages
100 /var/lib/dpkg/status

$ apt policy librda0
librda0:
Installed: (none)
Candidate: 0.0.5-1
Version table:
0.0.5-1 500
-10 Index of /ubuntu disco/universe amd64 Packages

$ apt policy mate-screensaver-common
mate-screensaver-common:
Installed: 1.20.0-1
Candidate: 1.20.3-3
Version table:
1.20.3-3 500
-10 Index of /ubuntu disco/universe amd64 Packages
-10 Index of /ubuntu disco/universe i386 Packages
*** 1.20.0-1 500
500 Index of /ubuntu bionic/universe amd64 Packages
500 Index of /ubuntu bionic/universe i386 Packages
100 /var/lib/dpkg/status

$ apt policy librda-common
librda-common:
Installed: (none)
Candidate: (none)
Version table:
0.0.5-1 -10
-10 Index of /ubuntu disco/universe amd64 Packages
-10 Index of /ubuntu disco/universe i386 Packages

$ sudo apt install librda0 mate-screensaver mate-screensaver-common
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:
librda0 : Depends: librda-common (>= 0.0.5-1) but it is not installable
E: Unable to correct problems, you have held broken packages.

Any ideas how to solve this problem?