app_queue.c: Fix error in Queue parameter documentation.

app_queue.c: Fix error in Queue parameter documentation.

When macro was removed in Asterisk 21, the parameter documentation in
code was not updated to reflect the correct numerization for gosub. It
still stated that it was the seventh parameter, but got shifted to the
sixth due to the removal of macro. This has been updated to correctly
reflect the parameter order, and a note has been added to the XML that
states this was done after the initial commit.

Fixes: #1534
UpgradeNote: As part of Asterisk 21, macros were removed from Asterisk.
This resulted in argument order changing for the Queue dialplan
application since the macro argument was removed. Upgrade notice was
missed when this was done, so this upgrade note has been added to
provide a record of such and a notice to users who may have not upgraded
yet.