use given plugin instead of plugin in config.toml

[HoeppJ]

At present the plugin used in a project is extracted out the config.toml.
Therefore, when there is already an existing project folder with a config.toml file, the plugin of the previous project, for which the project folder has also been used, will be used.
In some cases, e.g. when you want to create a hydraulic system for an ifc-file (PluginHydraulicSystem) and calculate the lca (PluginLCA) afterwards, this leads to bugs.