UI - REST Invoke Action - Cannot scroll through list of functions

[gregberns]

Minimal steps to reproduce the problem (not required if feature enhancement):

1. Open browser window so its only 700px hight
2. Create new flow, create new "REST Invoke" activity
3. Select Settings > Headers > under "Search" then expand "string" and "coerce"
4. Scroll down to the bottom of the list

Current behavior (how does the issue manifest):

Issue: You cannot scroll

Expected behavior:

Should be able to scroll through the list, but the scroll is locked, so you cannot get to the bottom of the list

Please tell us about your environment (Operating system, docker version, browser & web ui version, etc):
Using Chrome 76.0.3809.132 (Official Build) (64-bit)
Docker v0.9.0 flogo/flogo-docker

Flogo version (CLI & contrib/lib. If unknown, leave empty or state unknown): v0.9.0
flogo/flogo-docker

Additional information you deem important (e.g. issue happens only occasionally):