Replace qpid_host with qpid_hostname

This patch replaces `qpid_host` with `qpid_hostname` in both the
documentation and the config file sample. `qpid_host` has been shipped
as the parameter to specify qpid's hostname, although the correct one is
`qpid_hostname`.

DocImpact
Closes-bug 1242715

Change-Id: I25f2d0e505560e1762f7f059728c33c47a23439e
(cherry picked from commit 21ea5f6535dd484fa7934d07f3519fbda7e5f6ee)
Fixes wrong Qpid protocol configuration

notify_qpid.py is suffering from the same issue as described in
launchpad bug https://bugs.launchpad.net/oslo/+bug/1158807.
Instead of setting connection.transport, it is attempting to
set connection.protocol.

Fixes bug 1243821

Change-Id: Ice3e7ad917c158a5953475809f3f46f48fd6054d
(cherry picked from commit c04ebd1a77d5dcf226812fadab08257207641220)
Fixes error message encoding issue when using qpid

Making the message only consist of primitive types
before sending it by qpid.

Fixes bug 1242734

Change-Id: I3ff7a19af9a7671f955345ada6acfba8bf573c70
(cherry picked from commit 94b9e66360387d24548f165cc4c7ee67f5160a0c)
Merge "Replace qpid_host with qpid_hostname" into stable/havana
Merge "Fixes error message encoding issue when using qpid" into stable/havana
Merge "Fixes wrong Qpid protocol configuration" into stable/havana