privileges loop: Panic (Stack overflow)

[saimikiry]

Hello! I’ve found a bug similar to this previously fixed issue: #712

Any circular dependency in the privileges block causes the program to crash due to a stack overflow:

To reproduce the issue, you can use the standard configuration file with the following modification:

# `rw` privilege group lists write-only grants
  rw:
  - rw
  - __all_on_tables__
  - __all_on_sequences__