Fix missing libwebkitgtk

[tgmti]

Fix error to execute spoon

WARNING:  no libwebkitgtk-1.0 detected, some features will be unavailable
    Consider installing the package with apt-get or yum.
    e.g. 'sudo apt-get install libwebkitgtk-1.0-0'

[tescalada]

I have several fixes/features for this repo dependent on this patch. Should I submit them against this repo with a dependency on this patch landing, or submit them against the tgmti fork which my repo is forked from?

[tgmti]

I have several fixes/features for this repo dependent on this patch. Should I submit them against this repo with a dependency on this patch landing, or submit them against the tgmti fork which my repo is forked from?

Hello @tescalada, since I forked this repo, it hasn't receive any updates, or responses.
If U want to send your PR to tgmti/docker-pdi, I apreciate.