Fix so that operational store correctly removes bridge-other-configs

Before, if a bridge-other-configs entry was removed on ovsdb, we didn't
remove it from the operational store.

This is an artifact of using *merge* rather than *put*.
Using merge is *still* a good idea for us, but what was happening
was basically this.

Say we got a report in the operational store of

[bridge-other-configs1, bridge-other-configs2]

which we dutifully merged.

Then we got a report of
[bridge-other-configs2]

when that is *merged*... the protocol1 entry is left dangling,
because its a *merge*.  To compensate, we have to be *very*
specific about wanting to remove bridge-other-configs1.

Change-Id: Ic94b67b341bf7233c881e324f494c6701b622131
Signed-off-by: Ed Warnicke <eaw@cisco.com>