Galleries With Multiple Images Timeout in Creation

[jlamoreaux]

Describe the bug
Galleries being created with several high-res images take a long time being created and either cause the connection to timeout or use all available resources on the server.

To Reproduce
Steps to reproduce the behavior:

1. As an admin, go to /gallery/create
2. Add several high-res images. (More than 6 did the trick in my case)
3. Click create.
4. App seems to crash and restart on server.

Expected behavior
Multiple high quality images should be handled without any issues.

Additional context
Seems to be related to this issue: jimp-dev/jimp#153

[jlamoreaux]

Switching from JIMP to Sharp did the trick.