Fix format problem with empty objects
When printing empty objects, the closing curly brace was missing one
indentation level.
Example from the output of test_utils:
BEFORE FIX:
{
"foo": "bar",
"child": {
"grandchild": {
}
}
}
AFTER FIX:
{
"foo": "bar",
"child": {
"grandchild": {
}
}
}