Error processing MundoMapGrap: illegal variable name

[Sebastián Mancilla]

I updated Mundo and encountered this error:

Error detected while processing function <SNR>141_MundoSettingsGraph[12]..<SNR>141_MundoMapGraph:
line    2:
E461: Illegal variable name: a:value
line    3:
E121: Undefined variable: a:value
...

Seems that 3eb2018 broke the plugin.

$ vim --version
VIM - Vi IMproved 8.1 (2018 May 18, compiled Feb 13 2019 17:40:48)
macOS version
Included patches: 1-900