CMake failure if the hostname is too long

[branfosj]

If the hostname makes the string longer than the box then we get the failure below. This was with commit d7a9e87ed6a4a29479dc25fbf36a7bb556c3f5a3.

-- 
--   +---------------------------------------------------+
--   | NECI configuration now complete                   |
--   |                                                   |
--   | VERSION 1.0.0                                     |
--   | SHAID                                             |
--   | TYPE    RELEASE                                   |
CMake Error at cmake/neci_print_summary.cmake:32 (string):
  string begin index: 53 is out of range 0 - 51
Call Stack (most recent call first):
  cmake/neci_print_summary.cmake:45 (box_side)
  CMakeLists.txt:156 (neci_print_summary)

-- Configuring incomplete, errors occurred!

[mcocdawc]

Thank you very much! I see that you also already fixed it for your build tool chain. We'll probably do something similar.