TextEditor: Fix crash in SyntaxHighlighterRunner

Do not delete the pimpl before the thread had finished.
amends e4f5a0f50b

Change-Id: I3c0a27bd709ea759797e23f7e04e04a076012c3b
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/plugins/texteditor/syntaxhighlighterrunner.cpp

@@ -266,10 +266,10 @@ ThreadedSyntaxHighlighterRunner::ThreadedSyntaxHighlighterRunner(SyntaxHighLight
 
 ThreadedSyntaxHighlighterRunner::~ThreadedSyntaxHighlighterRunner()
 {
-    d.release();
     m_thread.requestInterruption();
     m_thread.quit();
     m_thread.wait();
+    d.release();
 }
 
 } // namespace TextEditor