Close test servers used by VA's HTTP tests (#7691)

Fixes #1989

va/http_test.go

@@ -1256,15 +1256,8 @@ func TestHTTPKeyAuthorizationFileMismatch(t *testing.T) {
 }
 
 func TestHTTP(t *testing.T) {
-	// NOTE: We do not attempt to shut down the server. The problem is that the
-	// "wait-long" handler sleeps for ten seconds, but this test finishes in less
-	// than that. So if we try to call hs.Close() at the end of the test, we'll be
-	// closing the test server while a request is still pending. Unfortunately,
-	// there appears to be an issue in httptest that trips Go's race detector when
-	// that happens, failing the test. So instead, we live with leaving the server
-	// around till the process exits.
-	// TODO(#1989): close hs
 	hs := httpSrv(t, expectedToken)
+	defer hs.Close()
 
 	va, log := setup(hs, 0, "", nil, nil)
 
@@ -1328,7 +1321,7 @@ func TestHTTP(t *testing.T) {
 
 func TestHTTPTimeout(t *testing.T) {
 	hs := httpSrv(t, expectedToken)
-	// TODO(#1989): close hs
+	defer hs.Close()
 
 	va, _ := setup(hs, 0, "", nil, nil)