Fix missing conditions variable in custom query manager.
Fix missing conditions variable in custom query manager.

Not all bases were covered for conditions variable. Pre-assign it
with empty Q() object.

Change-Id: I31c5eecb617c40f1562ac7a1f952bae10e40215f

Linaro/lava-server,Linaro/lava-server,Linaro/lava-server,Linaro/lava-server