http: correct the expected error for RC4

We must make sure that we're getting a certificate error from the
library so we know that we're testing the right thing.

tests/online/badssl.c

@@ -70,6 +70,8 @@ void test_online_badssl__old_cipher(void)
 	if (!g_has_ssl)
 		cl_skip();
 
-	cl_git_fail(git_clone(&g_repo, "https://rc4.badssl.com/fake.git", "./fake", NULL));
-	cl_git_fail(git_clone(&g_repo, "https://rc4.badssl.com/fake.git", "./fake", &opts));
+	cl_git_fail_with(GIT_ECERTIFICATE,
+			 git_clone(&g_repo, "https://rc4.badssl.com/fake.git", "./fake", NULL));
+	cl_git_fail_with(GIT_ECERTIFICATE,
+			 git_clone(&g_repo, "https://rc4.badssl.com/fake.git", "./fake", &opts));
 }