Harden message_callback against runtime error.

[Matthias-NIDEC]

OCPP Version

OCPP1.6

Describe the bug

Harden message_callback against runtime error, if the message form the backend can not be handled.
See #884

This catches set runttime_error inside ocpp/common/string.hpp
void set(const std::string& data) {
if (data.length() <= this->length) {
if (this->is_valid(data)) {
this->data = data;
} else {
throw std::runtime_error("String has invalid format");
}
} else {
throw std::runtime_error("String length (" + std::to_string(data.length()) +
") exceeds permitted length (" + std::to_string(this->length) + ")");
}
}

option would be, instead of runtime_error, cut the string.

E.g. Authorize.conf with partendId longer then 20 characters.

To Reproduce

No response

Anything else?

No response