Config is not provided if modules is not specified

[Sergei Parshev]

The issue is here: https://github.com/griddynamics/mpl/blob/master/src/com/griddynamics/devops/mpl/MPLManager.groovy#L84

config.modules ? Helper.mergeMaps(config.subMap(config.keySet()-'modules'), (config.modules[name] ?: [:])) : [:]

So when config.modules is empty (no keys inside) or no modules is set at all - it will return just an empty map.