URL for the maskable icon sends a 301 redirect to the home page

[andreban]

Describe the bug
The URL for the maskable icon listed in the Web Manifest is redirecting to https://squoosh.app/

To Reproduce
run :

curl -v https://squoosh.app/assets/icon-large-maskable.png

Expected behavior
An Image is returned

Actual Behaviour
A 301 redirect to /index.html happens

*   Trying 142.93.108.123...
* TCP_NODELAY set
* Connected to squoosh.app (142.93.108.123) port 443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
* successfully set certificate verify locations:
*   CAfile: /etc/ssl/cert.pem
  CApath: none
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
* TLSv1.2 (IN), TLS handshake, Server hello (2):
* TLSv1.2 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
* TLSv1.2 (IN), TLS handshake, Server finished (14):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS change cipher, Client hello (1):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* TLSv1.2 (IN), TLS change cipher, Client hello (1):
* TLSv1.2 (IN), TLS handshake, Finished (20):
* SSL connection using TLSv1.2 / ECDHE-RSA-AES128-GCM-SHA256
* ALPN, server accepted to use h2
* Server certificate:
*  subject: CN=*.squoosh.app
*  start date: Feb  7 15:15:31 2020 GMT
*  expire date: May  7 15:15:31 2020 GMT
*  subjectAltName: host "squoosh.app" matched cert's "squoosh.app"
*  issuer: C=US; O=Let's Encrypt; CN=Let's Encrypt Authority X3
*  SSL certificate verify ok.
* Using HTTP2, server supports multi-use
* Connection state changed (HTTP/2 confirmed)
* Copying HTTP/2 data in stream buffer to connection buffer after upgrade: len=0
* Using Stream ID: 1 (easy handle 0x7fdaf0806600)
> GET /assets/icon-large-maskable.png HTTP/2
> Host: squoosh.app
> User-Agent: curl/7.54.0
> Accept: */*
> 
* Connection state changed (MAX_CONCURRENT_STREAMS updated)!
< HTTP/2 301 
< content-length: 27
< content-type: text/plain; charset=utf-8
< date: Wed, 12 Feb 2020 10:15:54 GMT
< location: /index.html
< age: 30692
< server: Netlify
< cache-control: must-revalidate,max-age=3600
< x-nf-request-id: 452bebea-2495-498f-aa37-4b7c355446f6-7943439
< 
Redirecting to /index.html

[chriswthomson]

icon-large-maskable.png isn't in src/assets (to be copied to the build/public/dist folder). icon-small.png is though and I can't see this being used.