Scale a correction by a factor of a thousand that it was missing

The difference between two transitions' offsets is measured in
seconds, but we add it to a time in milliseconds; so it needs to be
scaled to fit.  Fortunately rarely enough applied that it hadn't
caused any reported problems.

Change-Id: I11f9f9e46d43d748220e072ad7504d4c8c5bf192
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qtimezoneprivate.cpp

@@ -402,7 +402,7 @@ QTimeZonePrivate::Data QTimeZonePrivate::dataForLocalTime(qint64 forLocalMSecs,
               0 < tran.atMSecsSinceEpoch - nextTran.atMSecsSinceEpoch
               = (nextTran.offsetFromUtc - tran.offsetFromUtc) * 1000
             */
-            int dstStep = nextTran.offsetFromUtc - tran.offsetFromUtc;
+            int dstStep = (nextTran.offsetFromUtc - tran.offsetFromUtc) * 1000;
             Q_ASSERT(dstStep > 0); // How else could we get here ?
             if (nextFirst) { // hint thought we needed nextTran, so use tran
                 tran.atMSecsSinceEpoch -= dstStep;