Fix regression from https://github.com/go-gitea/gitea/pull/30047.
Apparently tables have certain user-agent styles that center inside
`<th>` etc. Restored the original fomantic rules for these.
Before:
<img width="1332" alt="Screenshot 2024-03-25 at 21 59 33"
src="e06a5509-b505-4752-9b6e-91d5ed49f61d">
After:
<img width="1330" alt="Screenshot 2024-03-25 at 21 59 40"
src="6444817f-dd61-4a1e-a8b3-959c2780148d">
(cherry picked from commit dd75237c3492140140c7413d788bd961692048d8)
11765a8206