parse IP proxy header also if listening on UNIX domain socket

Fixes #867

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

httpd/internal_test.go

@@ -1532,6 +1532,18 @@ func TestJWTTokenCleanup(t *testing.T) {
 	stopCleanupTicker()
 }
 
+func TestAllowedProxyUnixDomainSocket(t *testing.T) {
+	b := Binding{
+		Address:      filepath.Join(os.TempDir(), "sock"),
+		ProxyAllowed: []string{"127.0.0.1", "127.0.1.1"},
+	}
+	err := b.parseAllowedProxy()
+	assert.NoError(t, err)
+	if assert.Len(t, b.allowHeadersFrom, 1) {
+		assert.True(t, b.allowHeadersFrom[0](nil))
+	}
+}
+
 func TestProxyHeaders(t *testing.T) {
 	username := "adminTest"
 	password := "testPwd"