gitlab: fix issue template

The two lines with the Buildroot version and the system os-release
details are rendered on a single line, "because Markdown".

Make that a two-item list, to be sure they are on properly rendered.

Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

.gitlab/issue_templates/default.md

@@ -33,8 +33,8 @@ _Note: issues missing any information may get closed without further ado._
 ---
 ### What I did
 
-**Buildroot commit sha1**: _get this with `git describe HEAD`_
-**Distribution of the build machine**: _get this with `NAME` and `VERSION` from `/etc/os-release`_
+- **Buildroot commit sha1**: _get this with `git describe HEAD`_
+- **Distribution of the build machine**: _get this with `NAME` and `VERSION` from `/etc/os-release`_
 
 _Here, describe what you did:_
 - _any special environment variables: CC, CXX, TARGET, CROSS_COMPILE, etc…_