fix(service): fix the return value of ListRepositories

[imobachgs]

Problem

ListRepositories D-Bus method just crashes. It is expected to return an array with contains the
return value as its first element. However, when there are no repositories, it just returns an empty
array. It causes Ruby D-Bus to fail because it cannot serialize a nil value.

Actually, the old code only works where there is a single repository.

Solution

Fix the return value. For comparison, you can check the following ListPatterns method.

Testing

• Tested manually

[ancorgs]

LGTM