Remove trailing space from QDebug stream

It's unexpected that all messages generated by the stream version
of qDebug and friends have a trailing space. It also makes switching
to categorized logging (which only supports the stream version) difficult,
since all autotests checking for debug output would have to be adapted.

Task-number: QTBUG-15256
Change-Id: I8d627a8379dc273d9689f5611184f03607b73823
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/io/qdebug.h

@@ -80,6 +80,8 @@ public:
     inline QDebug &operator=(const QDebug &other);
     inline ~QDebug() {
         if (!--stream->ref) {
+            if (stream->space && stream->buffer.endsWith(QLatin1Char(' ')))
+                stream->buffer.chop(1);
             if (stream->message_output) {
                 QT_TRY {
                     qt_message_output(stream->type,