caddyfile: advance cursor for claimed token in NewFromNextTokens() (#2971)

When we append a token to the new dispenser, we need to consume it in the parent, too; otherwise it gets scanned twice, which in this case messed up the nesting count which got decremented once too many times.
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f