### Purpose
`path` is for slash-separated paths (URLs, BEP protocol); local file
system paths should use `path/filepath`. Fixed in
`cmd/stdiscosrv/database.go` (3 sites) and
`internal/db/sqlite/db_test.go` (1 site).
### Testing
`go build ./cmd/stdiscosrv/...` and `go vet` pass.
Signed-off-by: Yasuhiro Matsumoto <mattn.jp@gmail.com>