Prometheus configuration reload problem

        prometheus_test.go:74:
            	Error Trace:	prometheus_test.go:59
            	            				prometheus_test.go:74
            	Error:      	Received unexpected error:
            	            	500: failed to reload config: couldn't load configuration (--config.file="/etc/prometheus/prometheus.yml"): parsing YAML file /etc/prometheus/prometheus.yml: yaml: control characters are not allowed

            	            	github.com/percona/pmm-managed/services/prometheus.(*Service).reload
            	            		/Users/aleksi/Code/Percona/PMM-2.0/src/github.com/percona/pmm-managed/services/prometheus/prometheus.go:127
            	            	github.com/percona/pmm-managed/services/prometheus.teardown
            	            		/Users/aleksi/Code/Percona/PMM-2.0/src/github.com/percona/pmm-managed/services/prometheus/prometheus_test.go:59
            	            	github.com/percona/pmm-managed/services/prometheus.TestPrometheus.func1
            	            		/Users/aleksi/Code/Percona/PMM-2.0/src/github.com/percona/pmm-managed/services/prometheus/prometheus_test.go:74
            	            	testing.tRunner
            	            		/usr/local/Cellar/go/1.12.9/libexec/src/testing/testing.go:865
            	            	runtime.goexit
            	            		/usr/local/Cellar/go/1.12.9/libexec/src/runtime/asm_amd64.s:1337
            	Test:       	TestPrometheus/Default