Warning, when module is disabled and not configured

[mageconsult]

When the module is not configured, the SOAP-request will not work. Then there will be a warning because of the iteration of a bool-value. Throws a warning in developer-mode in the backend in stores->configuration, regardless if module is enabled in config or not.

Files involved:
app/code/MDS/Collivery/Model/Customer/Address/Attribute/Source/Location.php
public function getLocations()

app/code/MDS/Collivery/Model/Customer/Address/Attribute/Source/Suburb.php
public function getSuburbs()

app/code/MDS/Collivery/Model/Customer/Address/Attribute/Source/Town.php
public function getTowns()