if its empty don't set it to empty string

Change-Id: I14e2461141332677c029877f6ab082b6f5dd2010
Reviewed-on: https://gerrit.libreoffice.org/60524
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

svx/source/dialog/fntctrl.cxx

@@ -1610,9 +1610,6 @@ void FontPrevWindow::Paint(vcl::RenderContext& rRenderContext, const tools::Rect
                 }
             }
 
-            if (pImpl->maText.isEmpty())
-                pImpl->maText = OUString();
-
             if (pImpl->maText.isEmpty())
             {   // fdo#58427: still no text? let's try that one...
                 pImpl->maText = makeRepresentativeTextForFont(LATIN, rFont);