Issue Summary

When using the map(markers) visualization type then the single marker image seems to be missing. It points me to this place:
https:///static/images/////node_modules/leaflet/dist/images/marker-icon-2x.png

Steps to Reproduce

1. Write this query select 24 as x, 60 as y
2. Choose Map (Markers) visualization
3. Pick x or y for latitude and longitude and observe how the browser shows a missing image icon in middle of the ocean somewhere

Technical details:

• Redash Version: latest (5.something)
• Browser/OS: Chrome (Windows)
• How did you install Redash: manually.. ?