compile fix llvm/clang

https://bugs.gentoo.org/740290

Signed-off-by: Joerg Bornkessel <hd_brummy@gentoo.org> (14 May 2021)
--- a/notifyosd.cpp
+++ b/notifyosd.cpp
@@ -128,7 +128,7 @@
 		delete osd;
 	osd = cOsdProvider::NewOsd(left, top);
 	// defines drawing area and color depth
-	tArea Area = { 0, 0, width-1, height-1, colorDepth };
+	tArea Area = { 0, 0, static_cast<int>(width-1), static_cast<int>(height-1), colorDepth };
 	osd->SetAreas(&Area, 1);
 	// draw osd frame, 2px thick
 	osd->DrawRectangle(0,             0,             width-1,               height-1,               clrBackground);