Slightly improve console trace readability

- Shorten cache busting string to take up less room in the browser console.

modules/ui_javascript.py

@@ -12,7 +12,7 @@ def webpath(fn):
     else:
         uri = fn
     uri = uri.replace('\\', '/')
-    uri = f'file={uri}?{os.path.getmtime(fn)}'
+    uri = f'file={uri}?{int(os.path.getmtime(fn))}'
     return uri