removed web midi error alert on startup

emscripten/project/purr-data/index.html

@@ -246,7 +246,6 @@
           WebMidi.enable(function (err) {
             if (err) {
               // if the browser doesn't support web midi, one can still use pd without it
-              alert("The Web MIDI API is not supported in this browser.\nPlease check: https://github.com/djipco/webmidi#browser-support");
               console.error("Midi: failed to enable midi", err);
             } else {
               isWebMidiSupported = true;