[SL.Core] Removed old test.

tests/SixLabors.Core.Tests/Primitives/RectangleFTests.cs

@@ -252,13 +252,5 @@ namespace SixLabors.Primitives.Tests
             var r = new RectangleF(5, 5.1F, 1.3F, 1);
             Assert.Equal(string.Format(CultureInfo.CurrentCulture, "RectangleF [ X={0}, Y={1}, Width={2}, Height={3} ]", r.X, r.Y, r.Width, r.Height), r.ToString());
         }
-
-        [InlineData(0, 0, 0, 0)]
-        [InlineData(5, -5, 0.2, -1.3)]
-        public void ToStringTestEmpty(float x, float y, float width, float height)
-        {
-            var r = new RectangleF(x, y, width, height);
-            Assert.Equal("RectangleF [ Empty ]", r.ToString());
-        }
     }
 }