Doc: Fix broken \qmlsignal links

Fix the breaks caused by the re-categorizing of \qmlsignal pages

Task-number: QTBUG-35846
Change-Id: I130941b7d13f450a629d6a13a9ec5baa77ddc5e7
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>

doc/src/frameworks-technologies/threads.qdoc

@@ -318,7 +318,7 @@
             WorkerScript instance. Call \l{WorkerScript::}{sendMessage()} to start the
             computation in a new thread. Let the script call WorkerScript::sendMessage()
             too, to pass the result back to the GUI thread. Handle the result in
-            \l{WorkerScript::}{onMessage} and update the GUI there.
+            \c onMessage and update the GUI there.
     \row
         \li Permanent
         \li Have an object living in another thread that can perform different

doc/src/whatsnew/whatsnew50.qdoc

@@ -228,7 +228,7 @@
       \list
        \li \l{Text::textFormat}{AutoText} format now switches to \c StyledText
            instead of \c{RichText}.
-       \li \l{Text::onLineLaidOut}{onLineLaidOut} handler is called for every
+       \li \l{Text::}{lineLaidOut} signal is emitted for every
            line during the layout process to give the option of positioning
            and/or resizing text as they are laid out.
        \li \l{Text::doLayout}{doLayout()} method can now trigger the text