main: bump RLIMIT_NOFILE for the root user substantially
On current kernels BPF_MAP_TYPE_LPM_TRIE bpf maps are charged against
RLIMIT_MEMLOCK even for privileged users that have CAP_IPC_LOCK. Given
that mlock() generally ignores RLIMIT_MEMLOCK if CAP_IPC_LOCK is set
this appears to be an oversight in the kernel. Either way, until that's
fixed, let's just bump RLIMIT_MEMLOCK for the root user considerably, as
the default is quite limiting, and doesn't permit us to create more than
a few TRIE maps.