EVerest affected by memory exhaustion in libocpp

EVerest is an EV charging software stack, and EVerest libocpp is a C++ implementation of the Open Charge Point Protocol. In libocpp prior to version 0.30.1, pointers returned by the `strdup` calls are never freed. At each connection attempt, the newly allocated memory area will be leaked, potentially causing memory exhaustion and denial of service. Version 0.30.1 fixes the issue.