lib573: do not compare double for exact match

tests/libtest/lib573.c

@@ -83,8 +83,8 @@ int test(char *URL)
   }
 
   curl_easy_getinfo(c, CURLINFO_CONNECT_TIME, &connect_time);
-  if (connect_time==0.0) {
-    fprintf(stderr, "connect time is 0.0\n");
+  if (connect_time <= 0.0) {
+    fprintf(stderr, "connect time is <=0.0\n");
     res = TEST_ERR_MAJOR_BAD;
   }