Fix stream server zones session metrics

* Stream server zones sessions with 4xx and 5xx statuses are now correctly exported. Previously they were always reported as 0.

go.mod

@@ -3,6 +3,6 @@ module github.com/nginxinc/nginx-prometheus-exporter
 go 1.12
 
 require (
-	github.com/nginxinc/nginx-plus-go-client v0.3.1
+	github.com/nginxinc/nginx-plus-go-client v0.4.0
 	github.com/prometheus/client_golang v0.9.2
 )

go.sum

@@ -4,8 +4,8 @@ github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
-github.com/nginxinc/nginx-plus-go-client v0.3.1 h1:oj3tG3v5Ei8v8RccCyGurpVE0jrBFp+EX08qIaaVkm4=
-github.com/nginxinc/nginx-plus-go-client v0.3.1/go.mod h1:DBAmdDP71tOhgFPdCMVusegzdKmLVpVL0nVcMX17pbY=
+github.com/nginxinc/nginx-plus-go-client v0.4.0 h1:/kBbXz3FXqc0y1d+so9CuXgvnaWNcV6yOcFZ+9EUGjE=
+github.com/nginxinc/nginx-plus-go-client v0.4.0/go.mod h1:DBAmdDP71tOhgFPdCMVusegzdKmLVpVL0nVcMX17pbY=
 github.com/prometheus/client_golang v0.9.2 h1:awm861/B8OKDd2I/6o1dy3ra4BamzKhYOiGItCeZ740=
 github.com/prometheus/client_golang v0.9.2/go.mod h1:OsXs2jCmiKlQ1lTBmv21f2mNfw4xf/QclQDMrYNZzcM=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910 h1:idejC8f05m9MGOsuEi1ATq9shN03HrxNkD/luQvxCv8=

vendor/modules.txt

@@ -4,7 +4,7 @@ github.com/beorn7/perks/quantile
 github.com/golang/protobuf/proto
 # github.com/matttproud/golang_protobuf_extensions v1.0.1
 github.com/matttproud/golang_protobuf_extensions/pbutil
-# github.com/nginxinc/nginx-plus-go-client v0.3.1
+# github.com/nginxinc/nginx-plus-go-client v0.4.0
 github.com/nginxinc/nginx-plus-go-client/client
 # github.com/prometheus/client_golang v0.9.2
 github.com/prometheus/client_golang/prometheus