remove client project since thee's already one (#50)

Author: SergeyMenshykh

A2A.slnx

@@ -9,7 +9,6 @@
   <Folder Name="/samples/">
     <Project Path="samples/A2ACli/A2ACli.csproj" />
     <Project Path="samples/AgentServer/AgentServer.csproj" />
-    <Project Path="samples/Client/Client.csproj" />
     <Project Path="samples/SemanticKernelAgent/SemanticKernelAgent.csproj" />
   </Folder>
   <Folder Name="/src/">