samples: fix build without threading support

samples/cpp/tutorial_code/videoio/orbbec_astra/orbbec_astra.cpp

@@ -4,6 +4,17 @@
 
 #include <list>
 #include <iostream>
+
+
+#if !defined(HAVE_THREADS)
+int main()
+{
+    std::cout << "This sample is built without threading support. Sample code is disabled." << std::endl;
+    return 0;
+}
+#else
+
+
 #include <thread>
 #include <mutex>
 #include <condition_variable>
@@ -200,3 +211,5 @@ int main()
 
     return 0;
 }
+
+#endif