Fix for some typos in the QAndroidJniObject documentation.

qualified was misspelled "qulified".

Change-Id: Ie38ec999f0c3b7146cc52c9a28c2a82d5d007355
Reviewed-by: Venugopal Shivashankar <venugopal.shivashankar@digia.com>
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>