Bug 13332: Fix conflict between 5304 and 10860

Bug 13332: Fix conflict between 5304 and 10860

These 2 bugs are in conflict.
The first one always join the issue table, the second one join on this
table too if the OnSiteCheckouts pref is enable.
So DBI raises an error if the pref is enabled (2 joins on the same
table).

This patch removes the conditional join.

Test plan:
Go on a detail record page with items and verify that items are list and
that the error no more appears in the log file.

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>
Reproduced the problem, the patch fixes it, no noticeable regression found.

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Works as described, items are visible again.
Passes tests and QA script.

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>