AP_HAL_SITL: catch more signal for correct exit

SIGINT is for ctrl-c
SIGHUP and SIGQUIT are use within term. If the term close before SITL, it will trigger one of those and then exit cleanly anyway

libraries/AP_HAL_SITL/HAL_SITL_Class.cpp

@@ -170,6 +170,12 @@ void HAL_SITL::setup_signal_handlers() const
     sa.sa_flags = SA_NOCLDSTOP;
     sa.sa_handler = HAL_SITL::exit_signal_handler;
     sigaction(SIGTERM, &sa, NULL);
+#if defined(HAL_COVERAGE_BUILD) && HAL_COVERAGE_BUILD == 1
+    sigaction(SIGINT, &sa, NULL);
+    sigaction(SIGHUP, &sa, NULL);
+    sigaction(SIGQUIT, &sa, NULL);
+#endif
+
 }
 
 /*