StartPos is always positive for http/https

StartPos is always positive for http/https

server.cc: In member function ‘bool ServerState::HeaderLine(std::string)’:
server.cc:198:72: warning: format ‘%llu’ expects argument of type ‘long long unsigned int*’, but argument 3 has type ‘long long int*’ [-Wformat=]
       else if (sscanf(Val.c_str(),"bytes %llu-%*u/%llu",&StartPos,&Size) != 2)

Git-Dch: Ignore
Reported-By: gcc -Wpedantic