message: fix: ensure backwards compatibility with the old GFF parser
  With spaces as separators between keys and values
diff: @@ -81,18 +81,27 @@ public:
  std::pair<std::string, std::string> parseAttribute(const std ::string& keyValStr) {
  + std::string separator = "=";
  +
  + // If there are no equal signs, then we use spaces as separator,
  + // for backwards compatibility with the old, non-compliant parser
  + // See: https://github.com/nextstrain/nextclade/pull/388
  + if (keyValStr.find(separator) == std::string::npos) {
  + separator = " ";
  + }
  +
  std::vector<std::string> keyVal;
  - boost::split(keyVal, keyValStr, boost::is_any_of(" ="));
  + boost::split(keyVal, keyValStr, boost::is_any_of(separator));
  if (keyVal.size() != 2) {
  throw ErrorGffParserInvalidAttribute(keyValStr);
  }
  auto& key = keyVal[0];
  - key = boost::remove_erase_if(key, boost::is_any_of(R"('" )"));
  + key = boost::trim_copy_if(key, boost::is_any_of(R"('" )"));// trim spaces and quotation marks on both ends
  auto& val = keyVal[1];
  - val = boost::remove_erase_if(val, boost::is_any_of(R"('" )"));
  + val = boost::trim_copy_if(val, boost::is_any_of(R"('" )"));// trim spaces and quotation marks on both ends
  if (key.empty() || val.empty()) {
  throw ErrorGffParserInvalidAttribute(keyValStr);
  