Guard socket closing just like socket opening (#84)

Guard socket closing just like socket opening (#84)

diff --git a/lib/prometheus_exporter/client.rb b/lib/prometheus_exporter/client.rb
index 9fa5855..ad5de14 100644
--- a/lib/prometheus_exporter/client.rb
+++ b/lib/prometheus_exporter/client.rb
@@ -128,8 +128,8 @@ module PrometheusExporter
           sleep 0.001
         end
         @worker_thread = nil
-      end
         close_socket!
+      end
     end
 
     private

GitHub sha: 951cf6fd