Fix tests

Author: zapadi

tests/redmine-net-api.Tests/Tests/HostTests.cs

@@ -13,7 +13,6 @@ public sealed class HostTests
         [InlineData(null)]
         [InlineData("")]
         [InlineData(" ")]
-        [InlineData("string.Empty")]
         [InlineData("localhost")]
         [InlineData("http://")]
         [InlineData("<invalid>")]