Reported here: https://github.com/bitcoin/bitcoin/pull/10244#issuecomment-378035305

Travis log here: https://travis-ci.org/bitcoin/bitcoin/jobs/361243719#L2810

Note the JSON exception:

```
test_framework.authproxy.JSONRPCException: The mempool was not loaded yet (-1) 
```

That exception was introduced here: https://github.com/bitcoin/bitcoin/commit/cb1e319fe9e198c9c5cf5236fe9af5a3d748b9e8#diff-a0c8f511d90e83aa9b5857e819ced344R1617

cc @jtimon 
#include <script/sigcache.h>
#include <script/standard.h>
#include <shutdown.h>
#include <timedata.h>
#include <tinyformat.h>
#include <txdb.h>
#include <txmempool.h>
#include <ui_interface.h>
#include <undo.h>
#include <util/system.h>
#include <util/moneystr.h>
#include <util/strencodings.h>
#include <validationinterface.h>
#include <warnings.h>
#include <future>
#include <sstream>
#include <boost/algorithm/string/replace.hpp>
#include <boost/thread.hpp>
#if defined(NDEBUG)
# error "Bitcoin cannot be compiled without assertions."
#endif
#define MICRO 0.000001
#define MILLI 0.001
/**
 * Global state
 */
namespace {
    struct CBlockIndexWorkComparator
    {
        bool operator()(const CBlockIndex *pa, const CBlockIndex *pb) const {