Bug#974888: growlight: Reproducibly segfaults on pressing F1

[Nick Black]

Regarding your request to document 'H', I hope you'll find this
commit most pleasing: 
https://github.com/dankamongmen/growlight/commit/899881ddd3cd1839fad01963c70ecb2faf17be71
This will be present in 1.2.19.