Metrics data are not correct collected in v0.5.0 release.

Problem: metrics are not correctly collected during artifacts collector with must-gather-metrics exporter.

Reason: URI is not correctly encoded when constructing the URL query to Prometheus, then the request is rejected by server.

Steps to reproduce:

• run standalone metrics collector: `oc adm must-gather --image=quay.io/opct/must-gather-monitoring:v0.5.0`
• check the errors in: `must-gather.local.//monitoring/prometheus/metrics/*.stderr`