Merge pull request #214 from grafana/compactor-alert-critical

Fix severity for CortexCompactorRunFailed alert.

Author: pracucci

cortex-mixin/alerts/compactor.libsonnet

@@ -70,7 +70,7 @@
             increase(cortex_compactor_runs_failed_total[2h]) > 1
           |||,
           labels: {
-            severity: 'warning',
+            severity: 'critical',
           },
           annotations: {
             message: |||