Release 7.6.0: Added possibility to delete a quota value once it is set through specifying a value less than zero

[Guest]

Added possibility to delete a quota value once it is set through specifying a value less than zero for parameter quota-value

CLI help text is changed accordingly:
--quota-value The numeric quota value specifying the max. number of items allowed for context.
Zero is unlimited. A value less than zero deletes the quota entry (and falls back to configured behavior)