loplugin:stringconstant

/home/noel/libo/desktop/source/lib/init.cxx:3571:22: error: rewrite call
of 'rtl::operator==' with empty string constant argument as call of
'rtl::OUString::isEmpty' [loplugin:stringconstant]
        if (aHeaders == "")

Change-Id: If0d8c411c6dd563622a855e209c0a5692c222abe

desktop/source/lib/init.cxx

@@ -3568,7 +3568,7 @@ static char* doc_getCommandValues(LibreOfficeKitDocument* pThis, const char* pCo
         }
 
         OUString aHeaders = pDoc->getRowColumnHeaders(aRectangle);
-        if (aHeaders == "")
+        if (aHeaders.isEmpty())
             return nullptr;
 
         OString aString = OUStringToOString(aHeaders, RTL_TEXTENCODING_UTF8);