EVerest has out-of-bounds read in DZG_GSH01 SLIP CRC parser that can crash powermeter driver

EVerest is an EV charging software stack. Prior to version 2025.12.0, is_message_crc_correct in the DZG_GSH01 powermeter SLIP parser reads vec[vec.size()-1] and vec[vec.size()-2] without checking that at least two bytes are present. Malformed SLIP frames on the serial link can reach is_message_crc_correct with vec.size() < 2 (only via the multi-message path), causing an out-of-bounds read before CRC verification and pop_back underflow. Therefore, an attacker controlling the serial input can reliably crash the process. Version 2025.12.0 fixes the issue.