Fix encoding mismatches in tst_QSqlQuery

Fix encoding mismatches in tst_QSqlQuery

The file has been UTF-8 encoded for years, which means that the line:
    QString longerBLOB( "abcdefghijklmnopqrstuvxyz¿äëïöü¡  " );

Loaded a mojibake into QString. Then, this data was stored as a blob
in the database by calling longerBLOB.toLatin1() (a QByteArray), and
reloaded for check using toString().

Once the QString default codec changes to UTF-8, the mojibake would
get fixed, and the test would fail. Make sure it doesn't happen.

Change-Id: If12d6124c973e4a1c1b7978d90fffb9aa5545c66
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>