Content type incorrect when file not wrapped in folder

[vasco-santos]

This happens at least for JSON files. See

$ curl -I -H Cache-control:no-cache https://bafkreidmzrmlxiqo4lgr3pqxai4fpmmyy6q74qnol3h6ooeuhwgp7npdea.ipfs.w3s.link/
HTTP/2 200
date: Thu, 13 Jul 2023 07:25:37 GMT
content-type: text/plain; charset=UTF-8
content-length: 527936
cf-ray: 7e5fcafd2e0e58ea-TXL
access-control-allow-origin: *
cache-control: public, max-age=29030400, immutable
etag: "bafkreidmzrmlxiqo4lgr3pqxai4fpmmyy6q74qnol3h6ooeuhwgp7npdea"
vary: Accept-Encoding
access-control-allow-methods: GET
access-control-expose-headers: Link
content-security-policy: default-src 'self' 'unsafe-inline' 'unsafe-eval' blob: data: https://*.w3s.link https://*.nftstorage.link https://*.dweb.link https://ipfs.io/ipfs/ https://*.githubusercontent.com https://tableland.network https://*.tableland.network ; form-action 'self'; navigate-to 'self'; connect-src 'self' blob: data: https://*.w3s.link https://*.nftstorage.link https://*.dweb.link https://ipfs.io/ipfs/ https://*.githubusercontent.com https://tableland.network https://*.tableland.network ; report-to csp-endpoint ; report-uri https://csp-report-to.web3.storage
reporting-endpoints: csp-endpoint="https://csp-report-to.web3.storage"
server-timing: request;dur=1061
x-dotstorage-anchor: 9e348406da565286c555cbcca08374b587766387a9f63902f7eb9c336def6133
x-dotstorage-resolution-id: https://freeway.dag.haus
x-dotstorage-resolution-layer: dotstorage-race
x-freeway-version: 2.7.2
server: cloudflare

$ curl -I -H Cache-control:no-cache https://bafkreidmzrmlxiqo4lgr3pqxai4fpmmyy6q74qnol3h6ooeuhwgp7npdea.ipfs.dweb.link/
HTTP/2 200
server: openresty
date: Thu, 13 Jul 2023 07:25:48 GMT
content-type: application/json
content-length: 527936
vary: Accept-Encoding
access-control-allow-methods: GET
cache-control: public, max-age=29030400, immutable
etag: "bafkreidmzrmlxiqo4lgr3pqxai4fpmmyy6q74qnol3h6ooeuhwgp7npdea"
x-ipfs-gateway-host: ipfs-bank16-fr2
x-ipfs-path: /ipfs/bafkreidmzrmlxiqo4lgr3pqxai4fpmmyy6q74qnol3h6ooeuhwgp7npdea/
x-ipfs-roots: bafkreidmzrmlxiqo4lgr3pqxai4fpmmyy6q74qnol3h6ooeuhwgp7npdea
x-ipfs-pop: ipfs-bank16-fr2
timing-allow-origin: *
access-control-allow-origin: *
access-control-allow-methods: GET, POST, OPTIONS
access-control-allow-headers: X-Requested-With, Range, Content-Range, X-Chunked-Output, X-Stream-Output
access-control-expose-headers: Content-Range, X-Chunked-Output, X-Stream-Output
x-ipfs-lb-pop: gateway-bank2-fr2
x-proxy-cache: MISS
strict-transport-security: max-age=31536000; includeSubDomains; preload
accept-ranges: bytes