Jammy liblablgtk3-ocaml, liblablgtksourceview3-ocaml, liblablgtk3-ocaml-dev, and liblablgtksourceview3-ocaml-dev 3.1.2-1 report the wrong version

On March 4, [my Coq launchpad package succeeded with](https://launchpadlibrarian.net/589055712/buildlog_ubuntu-jammy-amd64.coq_8.master~git~202203042103+23110-0~daily375-aedb9bc5f3~ubuntu22.04.1_BUILDING.txt.gz)
```
LablGtk3 and LablGtkSourceView3 found (3.1.1), with native threads:
=> native CoqIDE will be built.
```
However, on March 8, [the same build script failed due to](https://launchpadlibrarian.net/589689507/buildlog_ubuntu-jammy-amd64.coq_8.master~git~202203082103+23112-0~daily375-a0df849836~ubuntu22.04.1_BUILDING.txt.gz)
```
LablGtk3 and LablGtkSourceView3 found ([unspecified]), but too old (required >= 3.1.0, found [unspecified]):
=> no CoqIDE will be built.
```
The difference is that liblablgtk3-ocaml, liblablgtksourceview3-ocaml, liblablgtk3-ocaml-dev, and liblablgtksourceview3-ocaml-dev got upgraded from 3.1.1+official-1build2 to 3.1.2-1. Apparently `ocamlfind query -format %v lablgtk3` now gives "[unspecified]" instead of a real version number.