Hi,
It looks like Leaflet just removed the dist files from its website (your broken links).
Feel free to complain here if you think this is a mistake:
https://github.com/Leaflet/Leaflet/issuesBut there is a high chance this was done on purpose, to push people using the CDN instead (your 2 new links).
So you will very probably have to update all your old pages, sorry…
If you have compatibility issues with the new version, you could retrieve previous versions by trying to find the appropriate link on Leaflet CDN.
The previous link scheme is:
http://cdn.leafletjs.com/leaflet-0.7.5/leaflet.jsBut you will need to know which version you were previously using.
It looks like CloudFlare also provides such previous versions of Leaflet:
http://cdnjs.com/libraries/leafletHope this helps.