mesh11sd: update to version 3.1.1

mesh11sd: update to version 3.1.1

Maintainer: Rob White rob@blue-wave.net

Compile tested: All

Run tested: arm_cortex-a7_neon-vfpv4, mipsel_24kc, mips_24kc, aarch64_cortex-a53, x86-64
    On 23.5 and master/snapshot.

Description:
    mesh11sd (3.1.1)
    This release contains several bug fixes.
    These fixes include improved ndp scan and more reliable peer node identification.

Details can be found here:
    https://github.com/openNDS/mesh11sd/releases/tag/v3.1.1

Signed-off-by: Rob White <rob@blue-wave.net>