Updated redirect code used in https redirects

See https://developer.mozilla.org/en-US/docs/Web/HTTP/Redirections

301 redirections do not keep the request method intact, and can occasionally be changed from POST to GET

308 redirections always keep the request method, which is necessary for all POST search requests

app/routes.py

@@ -25,7 +25,7 @@ def before_request_func():
 
     if https_only and request.url.startswith('http://'):
         url = request.url.replace('http://', 'https://', 1)
-        code = 301
+        code = 308
         return redirect(url, code=code)
 
     json_config = json.load(open(CONFIG_PATH)) if os.path.exists(CONFIG_PATH) else {'url': request.url_root}