PROBLEM:
I am working to set up piwik. During the setup, I am at the second page "2. System Check", and everything is green except for GD > 2.x + Freetype (graphics), which is listed under the "Optional" field. There is no option to proceed.

OS: Fedora 25
Google Chrome 56.0.2924.76 (Official Build) (64-bit)
Revision cc6576b53870d39ddafd3574d951ff36d5f7218e-refs/branch-heads/2924@{#860}

Also tested:
Firefox 51.0.1 (64-bit)

SUGGESTED RESOLUTION:
If these items are truly optional but will impair some functionality, allow the user to proceed with a warning. If they are not optional, change the area to something that does not imply that the user should be allowed to go on without them.