Description of problem:
It is possible to get into the state when showing list of activation keys produces ISE. This issue is about ISE produced when there are duplicate values in the rhnset table.

Note the issue was discovered by pstudeni and investigated by jdobes.


Version-Release number of selected component (if applicable):
satellite-schema-5.7.0.27-1.el6sat.noarch (but others are affected as well)


How reproducible:
We were not able to reproduce it besides one case


Steps to Reproduce:
1. Unreliable reproducer:
   a. Delete lots (hundreds) of activation keys via spacecmd:
      # spacecmd -s ... -u ... -p ... activationkey_list \
          | grep "^1-" \
          | xargs spacecmd -s ... -u ... -p ... activationkey_delete -y
   b. During it is deleting, refresh Systems -> Activation keys multiple times
2. Reliable, but not real-world reproducer:
   a. To see the issue, lets break directly the DB:
      rhnschema=# INSERT INTO rhnset (user_id, label, element) VALUES (1, 'activation_keys', 123);
      rhnschema=# INSERT INTO rhnset (user_id, label, element) VALUES (1, 'activation_keys', 123);
      rhnschema=# INSERT INTO rhnset (user_id, label, element) VALUES (1, 'activation_keys', 123);
   b. Show duplicate rows:
      rhnschema=# select user_id, label, element, count(*) from rhnset group by user_id, label, element having count(*) > 1;
       user_id |      label      | element | count 
      ---------+-----------------+---------+-------
             1 | activation_keys |     123 |     3
      (1 row)
   c. Check ISE on Systems -> Activation Keys
   d. Fix it:
      rhnschema=# DELETE FROM rhnset WHERE user_id = 1 AND label = 'activation_keys' AND element = 123;
      DELETE 3


Actual results:
Problem is that when rhnset have some duplicate rows, there is a assert in the code that checks that only one row was deleted (pardon me if I reproduced what jdobes told me yesterday incorrectly).


Expected results:
Code should be able to handle this case.