Remove duplicated 'the' word.

The qtbase/examples/widgets/doc/src/boxes.qdoc does not have
duplicated 'the' word. This task is not needed by Qt 5.

Change-Id: I0bcc6fabe3cb819f6e9c5386973e594427a2cddf
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
remove misleading statement from ~QSqlDatabase()

The presence of the sentence "If this is the last QSqlDatabase object
that uses a certain database connection, the database connection is
automatically closed" is misleading, whether or not the statement is
true. It is about an internal detail of QSqlDatabase's implementation.
As such it is not appropriate for user documentation. The user should be
focused on how to use addDatabase(), cloneDatabase() and removeDatabase()
correctly.

Task-number: QTBUG-29481
Change-Id: I0c39584be260e13340834c34098368fcce4a7419
Reviewed-by: Florian Paul Schmidt <mista.tapas@gmx.net>
Reviewed-by: Sune Vuorela <sune@vuorela.dk>
Reviewed-by: Mark Brand <mabrand@mabrand.nl>
(cherry picked from qtbase/0b8065b5819efd8ba3741ea5703d5b95954b16c2)