fix(demonsect): update name and url

[julioreigen]

new website: https://seitacelestial.com/ I maintained the id, it's the same library, also updated the nsfw value to the correct value.

Browse	Manhwa	Reader

Checklist:

• [x] Updated source's version for individual source changes
• [x] Updated all sources' versions for template changes
• [x] Set appropriate nsfw value
• [x] Did not change id even if a source's name or language were changed
• [x] Tested the modifications by running it on the simulator or a test device

[julioreigen]

the old demonsect source should also be removed if this replaces it

I forgot, now it's removed 👍🏽