pgadmin3 tabs not properly themed with wxGTK3

Hello,

We are outphasing wxWidgets GTK2 build and we have been reported that
the tabs in pgadmin3 (which remains very popular) aren't themed properly
when wxGTK3 is used.

See below screenshot; unstable is the wxGTK3 build.

https://dev.solus-project.com/file/data/jzugkmqtn5ikapyg6p2o/PHID-FILE-3gp2fiwycdzejhjcy3pq/pg-c.png

Thank you!