Fix Blazor projects.

Tests/MQTTnet.Test.BlazorApp/Client/MQTTnet.Test.BlazorApp.Client.csproj

@@ -13,7 +13,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\..\..\..\Source\MQTTnet\MQTTnet.csproj" />
+    <ProjectReference Include="..\..\..\Source\MQTTnet\MQTTnet.csproj" />
     <ProjectReference Include="..\Shared\MQTTnet.Test.BlazorApp.Shared.csproj" />
   </ItemGroup>