Updated Plotly

ampel-firmware/web_server.cpp

@@ -41,7 +41,7 @@ namespace web_server {
             "<link rel='stylesheet' href='https://unpkg.com/purecss@2.0.6/build/pure-min.css'>"
             "<link rel='stylesheet' href='https://unpkg.com/purecss@2.0.6/build/grids-responsive-min.css'>"
             // JS Graphs:
-            "<script src='https://cdn.plot.ly/plotly-basic-1.58.2.min.js'></script>"
+            "<script src='https://cdn.plot.ly/plotly-basic-2.9.0.min.js'></script>"
             // Fullscreen
             "<meta name='viewport' content='width=device-width, initial-scale=1'>"
             // Refresh after every measurement.