message: unit-testsuites.cpp: fix hangup if file not found
  If run from the wrong directory, std::ifstream f("test/data/big-list-of-naughty-strings/blns.json"); will not find the file and thus f.eof() will never return true.
  Use canonical C++ file reading loop from instead.
diff: @@ -1346,13 +1346,11 @@ TEST_CASE("Big List of Naughty Strings")
  SECTION("roundtripping")
  {
  std::ifstream f("test/data/big-list-of-naughty-strings/blns.json");
  -
  - while (not f.eof())
  - {
  - // read line
  std::string line;
  - getline(f, line);
  + // read lines one by one, bail out on error or eof
  + while (getline(f, line))
  + {
  // trim whitespace
  line = trim(line);
  