Fix glossary generation

The glossary contained <indexterm> entries inside of
<glossterm>. This is wrong, they need to come after the glossterm, our
tools did not find any of the glossary terms that contained an
indexterm.

The grammar is:
glossentry ::=
(glossterm,acronym?,abbrev?,
 (indexterm)*,
 revhistory?,
 (glosssee|glossdef+))

This fixes building of the glossary for the Security Guide.

Reference:
https://lists.oasis-open.org/archives/docbook/200301/msg00077.html
http://docbook.org/tdg51/en/html/glossentry.html

Change-Id: Ic7f919ed5f9082b6adfa58d3c2c98357f07ce04e
Closes-Bug: #1347416
Merge "Fix glossary generation"