In #3916, I overlooked that `get_output_config` does not handle
wildcards unless the config is reloading, which is a remnant of older
iterations of the output config handling that went unnoticed due to
`output_find_config` handling it. With the current version of the
output config handling, having `get_output_config` handle wildcard
configs is actually preferable. This fixes having only a wildcard
output config in the config file or when connecting/enabling a new
output with only a wildcard config existing.