Raise 404 instead of returing it

[vstoykov]

Fixes #4451

[yakky]

probably worth merging in support branches too

[evildmp]

@vstoykov This should be covered by a test already (not sure where it would be exactly), but if there isn't one, we need one.

[vstoykov]

I will try to find a proper place to put the test and will update my pull request

[mkoistinen]

@vstoykov is this still on your radar?

[vstoykov]

Hi guys sorry for the delay. I was busy these days.

I also had some problems with running tests on my machine. I'm not sure if it is related with newer version of Firefox or something else but at the end I just ran the tests related to publishing process test_publisher (where I put my test).

I rebased my PR to current develop. I see that you put milestone 3.0.16 and this means that someone of you @yakky @mkoistinen will backport it right?

[yakky]

@vstoykov yes. Will do. Thanks for taking your time ti complete this pr

[vstoykov]

There are some problems with the tests with which I'm not familiar. Can you guys check the output of the travis?

[vxsx]

@vstoykov it seems some of the jobs were cancelled, I restarted them

[yakky]

@vstoykov all good now. @vxsx I'll merge first into support branch. I 'll take care of this

[yakky]

Fixed in support. Will forward port
Thanks @vstoykov for reporting this!