Fix the read-rif utils so that it reads correctly rif coming from prog with no input.

3 jobs for master in 7 minutes and 22 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
passed #15286
build

00:04:22

passed #10122
build

00:04:10

 
  Test
passed #10123
test_opam_test

00:03:00