(cmake) Stop using FetchContent cmake module to retrieve jsoncpp third party dependency

CMakeLists.txt

@@ -258,11 +258,7 @@ if (USE_WS OR USE_TEST)
       GIT_REPOSITORY "https://github.com/gabime/spdlog"
       GIT_TAG "v1.8.0") 
 
-  FetchContent_Declare(jsoncpp
-      GIT_REPOSITORY "https://github.com/open-source-parsers/jsoncpp"
-      GIT_TAG "1.9.4") 
-
-  FetchContent_MakeAvailable(spdlog jsoncpp)
+  FetchContent_MakeAvailable(spdlog)
 
   if (USE_WS)
       add_subdirectory(ws)