fix the below build error by correcting the typo (tring -> string)
hello++5.cxx: In member function 'virtual void CThingSayer::ThrowMyThing(const char*)':
hello++5.cxx:157:21: error: 'tring' was not declared in this scope
157 | throw MyException(tring(czSayThis));
| ^~~~~
Signed-off-by: Abhishek Akkabathula <a.akkabathul@samsung.com>
