Hopefully fix issues with werkzeug not allowing auto_rx to exit. Handle SDR exceptions within scan loop on non-linux systems

auto_rx/autorx/scan.py

@@ -865,12 +865,16 @@ class SondeScanner(object):
                 self.log_warning("SDR produced no output... resetting and retrying.")
                 self.error_retries += 1
                 # Attempt to reset the SDR, if possible.
-                reset_sdr(
-                    self.sdr_type, 
-                    rtl_device_idx = self.rtl_device_idx, 
-                    sdr_hostname = self.sdr_hostname, 
-                    sdr_port = self.sdr_port
-                )
+                try:
+                    reset_sdr(
+                        self.sdr_type, 
+                        rtl_device_idx = self.rtl_device_idx, 
+                        sdr_hostname = self.sdr_hostname, 
+                        sdr_port = self.sdr_port
+                    )
+                except Exception as e:
+                    self.log_error(f"Caught error when trying to reset SDR - {str(e)}")
+
                 for _ in range(10):
                     if not self.sonde_scanner_running:
                         break

auto_rx/autorx/web.py

@@ -290,7 +290,11 @@ def shutdown_flask(shutdown_key):
     global flask_shutdown_key
     # Only shutdown if the supplied key matches our shutdown key
     if shutdown_key == flask_shutdown_key:
-        flask.request.environ.get("werkzeug.server.shutdown")()
+        shutdown_function = flask.request.environ.get("werkzeug.server.shutdown")
+        if shutdown_function:
+            shutdown_function()
+        else:
+            logging.debug("Unable to stop this version of Werkzeug, continuing...")
 
     return ""
 
@@ -586,6 +590,8 @@ def start_flask(host="0.0.0.0", port=5000):
 
     # Start up Flask
     flask_app_thread = Thread(target=flask_thread, kwargs={"host": host, "port": port})
+    # Set thread to be a daemon, so python will quit nicely.
+    flask_app_thread.daemon = True
     flask_app_thread.start()
     logging.info("Started Flask server on http://%s:%d" % (host, port))