[BUG] No events generated with regex in stanza

[jmeixensperger]

Describe the bug
No events are generated with my stanza that includes a regex pattern.

To Reproduce
Steps to reproduce the behavior:
use attached conf/samples

Expected behavior
Events generated from multiple files

Actual behavior
No events

Sample files and eventgen.conf file
eventgen.conf:
[file\d+\.txt]
mode = sample
outputMode = stdout
end = 1

Do you run eventgen with SA-eventgen?
No