Add back consumeAndClose functionality. (#7608)

* consume bodies for action button integrations, webrtc gateway, oauth
endpoint

* Fixing a couple more places, switching to io.Copy to ioutil.Discard, adding a comment to help prevent future performance regressions

app/server.go

@@ -5,6 +5,8 @@ package app
 
 import (
 	"crypto/tls"
+	"io"
+	"io/ioutil"
 	"net"
 	"net/http"
 	"strings"
@@ -208,3 +210,11 @@ func (a *App) StopServer() {
 		a.Srv.GracefulServer = nil
 	}
 }
+
+// This is required to re-use the underlying connection and not take up file descriptors
+func consumeAndClose(r *http.Response) {
+	if r.Body != nil {
+		io.Copy(ioutil.Discard, r.Body)
+		r.Body.Close()
+	}
+}