message: Improve test by avoiding a potential use after free of a temporary std::string.
diff: @@ -1728,11 +1728,11 @@ TEST_TYPES(StringIndex_Insensitive, non_nullable, nullable)
  {
  constexpr bool case_insensitive = true;
  const char* needle = "john";
  - StringData upper_needle = case_map(needle, true);
  + auto upper_needle = case_map(needle, true);
  ndx.find_all(results, needle, case_insensitive);
  CHECK_EQUAL(17, results.size());
  for (size_t i = 0; i < results.size(); ++i) {
  - StringData upper_result = case_map(col.get(results.get(i)), true);
  + auto upper_result = case_map(col.get(results.get(i)), true);
  CHECK_EQUAL(upper_result, upper_needle);
  }
  