Fix no-ct in test/ct_test.c

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1890)
diff --git a/test/ct_test.c b/test/ct_test.c
index edd02af..1cfd0d1 100644
--- a/test/ct_test.c
+++ b/test/ct_test.c
@@ -555,4 +555,10 @@
 
     return result;
 }
+#else
+int test_main(int argc, char *argv[])
+{
+    printf("No CT support\n");
+    return 0;
+}
 #endif