Describe the bug
After upgrading to 1.34 from 1.33 the PROMETHEUS_SERVER_URL value is not read anymore.

Using v1.33

{"level":"info","ts":1652451118.0158124,"caller":"metricsstore/reader.go:94",
 "msg":"Prometheus reader initialized","addr":"http://172.16.128.175:9090"} 

And v1.34, which shows the default value.

{"level":"info","ts":1652451438.1780195,"caller":"metricsstore/reader.go:94",
 "msg":"Prometheus reader initialized","addr":"http://localhost:9090"}

To Reproduce
Steps to reproduce the behavior:

1. Run 1.33 with monitor tab
2. Upgrade to 1.34
3. Notice the 500's error in the monitor tab

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
If applicable, add screenshots to help explain your problem.

Version (please complete the following information):

• OS: Linux
• Jaeger version: 1.34
• Deployment: Docker

What troubleshooting steps did you try?

I was using PROMETHEUS_SERVERURL env variable and switched to a config-file, same issue. Here is the config file.

log-level: info

admin:
  http:
    host-port: "0.0.0.0:29937"

query:
  base-path: "/jaeger"
  grpc-server:
    host-port: "0.0.0.0:24507"
  http-server:
    host-port: "0.0.0.0:25050"

es:
  server-urls: "http://opensearch-tracing.service.consul:9200"

prometheus:
  server-url: "http://172.16.128.175:9090"

Additional context

Asked for help on Slack: https://cloud-native.slack.com/archives/CGG7NFUJ3/p1652443407988039