trigger_mask not present using tohdf5

Summary

When using tohdf5 on a root file, the trigger_mask parameter is not found in the event_info group of the resulting h5 file.

Environment

• KM3Pipe version (km3pipe --version): 8.16.0
• Python version (python --version): 2.7.16
• OS: (uname -a) Linux cca004 3.10.0-957.12.2.el7.x86_64 #1 (closed) SMP Tue May 14 21:24:32 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

Additional information

(The following are optional but may be relevant.)

• HDF5 metadata (h5info /path/to/relevant/file.h5)
• ROOT file metadata (JPrintMeta -f /path/to/relevant/file.root):
• Jpp version (only if relevant, JPrint -v)

Describe the current bug behavior

trigger_mask is not event_info, even though it is present in the root file.

Describe the expected correct behavior

trigger_mask in event_info of the resulting h5 file.

Steps to reproduce

Download a file from irods, e.g. from /in2p3/km3net/data/trigger/JTR/KM3NeT_00000029/v0.3/2/, then use tohdf5 on it.

Relevant logs and/or screenshots

(Paste any relevant logs - please use code blocks (put the code between ```) to format console output, logs, and code as it's very hard to read otherwise.)