Reuse fasthttp client

struct_config.go

@@ -5,6 +5,7 @@ import (
 	graphql "github.com/lukaszraczylo/go-simple-graphql"
 	libpack_logging "github.com/lukaszraczylo/graphql-monitoring-proxy/logging"
 	libpack_monitoring "github.com/lukaszraczylo/graphql-monitoring-proxy/monitoring"
+	"github.com/valyala/fasthttp"
 )
 
 // config is a struct that holds the configuration of the application.
@@ -28,6 +29,8 @@ type config struct {
 		RoleRateLimit    bool
 		RoleFromHeader   string
 		GQLClient        *graphql.BaseClient
+		FastProxyClient  *fasthttp.Client
+		proxy            string
 	}
 
 	Cache struct {