fix warning

Graphics/drawContext.cpp

@@ -422,7 +422,7 @@ void drawContext::initProjection(int xpick, int ypick, int wpick, int hpick)
           Msg::Error("Could not load valid background image");
           // make sure we don't try to load it again
           for(int i = 0; i < 3; i++) _bgImage.push_back(0);
-          _bgImageSize[0] = _bgImageSize[1] = 1.;
+          _bgImageSize[0] = _bgImageSize[1] = 1;
         }
         if(img) delete img;
       }