[fix, UX] frontlightwidget: More space for text and centering
[fix, UX] frontlightwidget: More space for text and centering

Otherwise clock display will have a line break for low DPI (see issue

Frenzie/koreader,NiLuJe/koreader,pazos/koreader,Markismus/koreader,lgeek/koreader,koreader/koreader,mihailim/koreader,Frenzie/koreader,houqp/koreader,poire-z/koreader,Hzj-jie/koreader,NiLuJe/koreader,koreader/koreader,poire-z/koreader,mwoz123/koreader