conf/yaml: limit recursion depth while paring YAML
A deeply nested YAML file can cause a stack-overflow while
reading in the configuration to do the recursive parser. Limit
the recursion level to something sane (128) to prevent this
from happening.
The default Suricata configuration has a recursion level of 128
so there is still lots of room to grow (not that we should).
Redmine ticket:
https://redmine.openinfosecfoundation.org/issues/3630
(cherry picked from commit
4dc80a6e6f9b396de5dc25d3468522316c4661d0)