As @Keltari mentioned, many apps bundle their own Java version along with the application because it saves them from relying on your installed Java which they know nothing about.
You can open the DeltaWalker application in Finder to see that this is what is happening here. (I did this with a new copy of the DeltaWalker dmg, but yours should be the same). Find the DeltaWalker "Application", Ctrl-click or right-click on it, and choose "Show Package Contents". Navigate to
Contents\PlugIns\jre\Contents\Home\ to see the version of Java that is being used by the application. You can go to this path in a Terminal window, go into the
bin folder, and run
java -version to confirm that it is the same version you are seeing in the User-Agent. (I can't check this myself, given that I am actually picking apart the application using 7-zip on a Windows computer.)
It is theoretically possible to just replace this Java version with a newer one, but I would hesitate to do that, given how tightly tied-together application components may be and given that DeltaWalker bundles many other dependencies along with it (helper executables and JAR plugins) which may also have issues.
If you are not using the most recent version of the application, you should update it if you can. If you can't, or if the most recent version is still too old, you should contact Deltopia Support.