Revert "Do not raise an exception on no input processor."
Revert "Do not raise an exception on no input processor."

This reverts commit 77cfa98526f43919619dacf27a0f5c2644313985.

Reason: this commit breaks writing reports.

0xPoly/ooni-probe,lordappsec/ooni-probe,juga0/ooni-probe,juga0/ooni-probe,kdmurray91/ooni-probe,lordappsec/ooni-probe,Karthikeyan-kkk/ooni-probe,lordappsec/ooni-probe,kdmurray91/ooni-probe,0xPoly/ooni-probe,Karthikeyan-kkk/ooni-probe,kdmurray91/ooni-probe,juga0/ooni-probe,0xPoly/ooni-probe,kdmurray91/ooni-probe,0xPoly/ooni-probe,Karthikeyan-kkk/ooni-probe,Karthikeyan-kkk/ooni-probe,lordappsec/ooni-probe,juga0/ooni-probe