Doc: Circumvented qdoc parsing by removing '!'

Qdoc gave warning "Cannot link this to anything"

Task-number: QTBUG-43810
Change-Id: Id903040ed7b2860a2ec64a52f7fbe8269c6927b0
Reviewed-by: Martin Smith <martin.smith@theqtcompany.com>
Reviewed-by: Topi Reiniö <topi.reinio@theqtcompany.com>

src/corelib/tools/qstring.cpp

@@ -5686,7 +5686,7 @@ QString QString::rightJustified(int width, QChar fill, bool truncate) const
 */
 
 namespace QUnicodeTables {
-/*!
+/*
     \internal
     Converts the \a str string starting from the position pointed to by the \a
     it iterator, using the Unicode case traits \c Traits, and returns the