susepaste script: silently fails if script output more than ~2000 lines are pasted

[okurz]

calling "susepaste" with output from a script bigger than about 2000 lines returns the paste address without an error but the link returns a "404 not found" error. 2048 still work, 4096 do not.

[wsxy162]

Popuping a dialog to notify the user has pasted too much text or the max limitation would be great.