Fix memleaks found with AddressSanitizer/LeakSanitizer

Found with:
ASAN_OPTIONS="detect_odr_violation=1,strip_path_prefix=$(pwd)/" build/sdrangel

Fixes:
Direct leak of 448 byte(s) in 2 object(s) allocated from:
    #0 0x7f78cd8f46b8 in operator new(unsigned long) ../../../../src/libsanitizer/asan/asan_new_delete.cpp:95
    f4exb#1 0x7f788e0e9d9c in GS232ControllerWorker::MsgConfigureGS232ControllerWorker::create(GS232ControllerSettings const&, QList<QString> const&, bool) sdrangel/plugins/feature/gs232controller/gs232controllerworker.h:51
    f4exb#2 0x7f788e0eeedf in GS232Controller::applySettings(GS232ControllerSettings const&, QList<QString> const&, bool) sdrangel/plugins/feature/gs232controller/gs232controller.cpp:291
    f4exb#3 0x7f788e0ec595 in GS232Controller::handleMessage(Message const&) sdrangel/plugins/feature/gs232controller/gs232controller.cpp:156
    f4exb#4 0x7f78cabe899f in Feature::handleInputMessages() sdrangel/sdrbase/feature/feature.cpp:46
    f4exb#5 0x7f78ca9f9b5c in Feature::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) build-sdrangel-Desktop_qt5-Debug/sdrbase/sdrbase_autogen/3DM3QXXG3A/moc_feature.cpp:89
    f4exb#6 0x7f78c7f05fcc  (/lib/x86_64-linux-gnu/libQt5Core.so.5+0x305fcc) (BuildId: ed2abb344a128279a866aa6c4a79f3fa5c87c59e)
    f4exb#7 0x7f78caa0584a in MessageQueue::messageEnqueued() build-sdrangel-Desktop_qt5-Debug/sdrbase/sdrbase_autogen/KH43KSYMFX/moc_messagequeue.cpp:131
    f4exb#8 0x7f78cad19c77 in MessageQueue::push(Message*, bool) sdrangel/sdrbase/util/messagequeue.cpp:55
    f4exb#9 0x7f788e142936 in GS232ControllerGUI::applySettings(QStringList const&, bool) sdrangel/plugins/feature/gs232controller/gs232controllergui.cpp:969
    f4exb#10 0x7f788e142727 in GS232ControllerGUI::applySetting(QString const&) sdrangel/plugins/feature/gs232controller/gs232controllergui.cpp:960
    f4exb#11 0x7f788e133c26 in GS232ControllerGUI::onWidgetRolled(QWidget*, bool) sdrangel/plugins/feature/gs232controller/gs232controllergui.cpp:206
    f4exb#12 0x7f788e0e25d9 in GS232ControllerGUI::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) build-sdrangel-Desktop_qt5-Debug/plugins/feature/gs232controller/featuregs232controller_autogen/EWIEGA46WW/moc_gs232controllergui.cpp:234
    f4exb#13 0x7f78c7f05fcc  (/lib/x86_64-linux-gnu/libQt5Core.so.5+0x305fcc) (BuildId: ed2abb344a128279a866aa6c4a79f3fa5c87c59e)
    f4exb#14 0x7f78ccdcd9a1 in RollupContents::widgetRolled(QWidget*, bool) build-sdrangel-Desktop_qt5-Debug/sdrgui/sdrgui_autogen/DMHXEJ42XS/moc_rollupcontents.cpp:146
    f4exb#15 0x7f78cd06a080 in RollupContents::eventFilter(QObject*, QEvent*) sdrangel/sdrgui/gui/rollupcontents.cpp:403
    f4exb#16 0x7f78c7ecc4b2 in QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject*, QEvent*) (/lib/x86_64-linux-gnu/libQt5Core.so.5+0x2cc4b2) (BuildId: ed2abb344a128279a866aa6c4a79f3fa5c87c59e)

and more

plugins/feature/gs232controller/gs232controller.cpp

@@ -288,11 +288,10 @@ void GS232Controller::applySettings(const GS232ControllerSettings& settings, con
         m_selectedPipe = m_availableChannelOrFeatureHandler.registerPipes(settings.m_source, {"target"});
     }
 
-    GS232ControllerWorker::MsgConfigureGS232ControllerWorker *msg = GS232ControllerWorker::MsgConfigureGS232ControllerWorker::create(
-        settings, settingsKeys, force
-    );
-
     if (m_worker) {
+        GS232ControllerWorker::MsgConfigureGS232ControllerWorker *msg = GS232ControllerWorker::MsgConfigureGS232ControllerWorker::create(
+            settings, settingsKeys, force
+            );
         m_worker->getInputMessageQueue()->push(msg);
     }