Fix the docs on when setDocument() deletes the previous document

Change-Id: I08d162a1c1e1765213205e63183ed75b2491374d
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>

src/widgets/widgets/qtextedit.cpp

@@ -755,8 +755,8 @@ Qt::Alignment QTextEdit::alignment() const
 
     \note The editor \e{does not take ownership of the document} unless it
     is the document's parent object. The parent object of the provided document
-    remains the owner of the object. The editor does not delete any previously
-    assigned document, even if it is a child of the editor.
+    remains the owner of the object. If the previously assigned document is a
+    child of the editor then it will be deleted.
 */
 void QTextEdit::setDocument(QTextDocument *document)
 {