message: test: Drop excessive locking in CAddrManTest::SimConnFail
  The unit test is single threaded, so there's no need to hold the mutex
  between Good() and Attempt().
  This change avoids recursive locking in the CAddrMan::Attempt function.
diff: @@ -74,9 +74,9 @@ public:
  // Simulates connection failure so that we can test eviction of offline nodes
  void SimConnFail(const CService& addr)
  {
  - LOCK(cs);
  int64_t nLastSuccess = 1;
  - Good_(addr, true, nLastSuccess); // Set last good connection in the deep past.
  + // Set last good connection in the deep past.
  + Good(addr, true, nLastSuccess);
  bool count_failure = false;
  int64_t nLastTry = GetAdjustedTime()-61;
  