wrong error message for "file not found"

[skyper]

I get a message that there exists no import-filter instead of a message "file not found"

I did start josm from the console and forgot to add file-extension -> file does not exist.

r3961

[mjulius]

I suppose JOSM is first determining whether it could handle the file before actually trying to open it.

[skyper]

Maybe it should first check whether the file exist before doing anything else.

[skyper]

Closed as duplicate of #4743.