Small fix for to small sized textures

Vocaluxe/Lib/Draw/CDirect3D.cs

@@ -886,11 +886,15 @@ namespace Vocaluxe.Lib.Draw
                     {
                         w = newW;
                         h = (int)Math.Round(w / ratio);
+                        if (h == 0)
+                            h = 1;
                     }
                     else
                     {
                         h = newH;
                         w = (int)Math.Round(h * ratio);
+                        if (w == 0)
+                            w = 1;
                     }
                     //Create a new Bitmap with the new sizes
                     bmp2 = new Bitmap(w, h);

Vocaluxe/Lib/Draw/COpenGL.cs

@@ -713,12 +713,16 @@ namespace Vocaluxe.Lib.Draw
             if (w > maxSize)
             {
                 h = (int)Math.Round((float)maxSize / bmp.Width * bmp.Height);
+                if (h == 0)
+                    h = 1;
                 w = maxSize;
             }
 
             if (h > maxSize)
             {
                 w = (int)Math.Round((float)maxSize / bmp.Height * bmp.Width);
+                if (w == 0)
+                    w = 1;
                 h = maxSize;
             }