Bug: iOS client fails to receive messages due to Cloudflare injecting invalid priority header

[ksurl]

log:

2022/06/30 17:00:13 DEBUG 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f HTTP GET /APP/json?poll=1&since=vN1R3yK4zHhO Dispatching request
2022/06/30 17:00:13 TRACE 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f HTTP GET /APP/json?poll=1&since=vN1R3yK4zHhO Entire request (headers and body):
GET /APP/json?poll=1&since=vN1R3yK4zHhO HTTP/1.1
Accept: */*
Cdn-Loop: cloudflare
Cf-Ray: 723adc32fc02523f-LAX
Cf-Visitor: {"scheme":"https"}
Accept-Encoding: gzip
Accept-Language: en-US,en;q=0.9
Cf-Ipcountry: US
X-Forwarded-For: 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f, 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f
X-Forwarded-Host: ntfy.DOMAIN
X-Forwarded-Proto: https
X-Forwarded-Ssl: on
Authorization: Basic AUTH
Cf-Connecting-Ip: 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f
Connection: close
X-Real-Ip: 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f
User-Agent: ntfy/1.2 (build 3; iOS 15.5.0)
Cf-Warp-Tag-Id: f6e8ef16-b59e-49c4-bab3-7f8a619ab082
Priority: u=3
2022/06/30 17:00:13 DEBUG 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f HTTP GET /APP2/json?poll=1&since=all Dispatching request
2022/06/30 17:00:13 TRACE 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f HTTP GET /APP2/json?poll=1&since=all Entire request (headers and body):
GET /APP2/json?poll=1&since=all HTTP/1.1
Authorization: Basic AUTH
Cdn-Loop: cloudflare
Accept-Language: en-US,en;q=0.9
Cf-Ipcountry: US
Cf-Ray: 723adc3308ff7ad8-LAX
Cf-Visitor: {"scheme":"https"}
X-Forwarded-Host: ntfy.DOMAIN
User-Agent: ntfy/1.2 (build 3; iOS 15.5.0)
Accept-Encoding: gzip
Priority: u=3
Connection: close
X-Forwarded-Proto: https
Cf-Connecting-Ip: 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f
X-Real-Ip: 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f
Accept: */*
Cf-Warp-Tag-Id: f6e8ef16-b59e-49c4-bab3-7f8a619ab082
X-Forwarded-For: 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f, 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f
X-Forwarded-Ssl: on
2022/06/30 17:00:13 DEBUG 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f HTTP GET /APP/json?poll=1&since=vN1R3yK4zHhO HTTP stream connection opened
2022/06/30 17:00:13 DEBUG 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f HTTP GET /APP/json?poll=1&since=vN1R3yK4zHhO HTTP stream connection closed
2022/06/30 17:00:13 INFO 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f HTTP GET /APP/json?poll=1&since=vN1R3yK4zHhO Connection closed with HTTP 500 (ntfy error 50001): invalid priority
2022/06/30 17:00:13 DEBUG 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f HTTP GET /APP2/json?poll=1&since=all HTTP stream connection opened
2022/06/30 17:00:13 DEBUG 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f HTTP GET /APP2/json?poll=1&since=all HTTP stream connection closed
2022/06/30 17:00:13 INFO 2607:fb91:2a2:e023:508e:6746:ebcd:3f4f HTTP GET /APP2/json?poll=1&since=all Connection closed with HTTP 500 (ntfy error 50001): invalid priority

Priority: u=3

HTTP error 500
ntfy error 50001 invalid priority

[ksurl]

duplicate of #351