Fix occasional hangups on exit

src/Compositor.cpp

@@ -233,6 +233,14 @@ void CCompositor::cleanup() {
     wl_display_terminate(m_sWLDisplay);
 
     m_sWLDisplay = nullptr;
+
+    // kill the PID with a sigkill after 2 seconds
+    const auto PID = getpid();
+
+    std::string call = "sleep 2 && kill -9 " + std::to_string(PID);
+
+    execl("/bin/sh", "/bin/sh", "-c", call.c_str(), ">", "/dev/null", nullptr); // this is to prevent that random "freezing"
+                                                                                // the PID should not be reused.
 }
 
 void CCompositor::startCompositor() {