Empty glob not always returns an error

[jcamiel]

With Hurl 4.2.0:

Given a directory /tmp/a/ that contains Hurl files and a directory /tmp/b/ that does not contains Hurl files:

$ hurl --glob '/tmp/a/*.hurl' --glob '/tmp/b/*.hurl'
# ...
# => test in /tmp/a/ executed
# ...

Reversing the two globs, we have an error:

$ hurl --glob '/tmp/b/*.hurl' --glob '/tmp/a/*.hurl' 
error: hurl: cannot access '/tmp/b/*.hurl': No such file or directory