config: free_bar: Check if outputs is NULL.
config: free_bar: Check if outputs is NULL.

bar_config.outputs is NULL if no output is explicitly defined in config
(ie. use for for all outputs).

taiyu-len/sway,crondog/sway,sleep-walker/sway,johalun/sway,1ace/sway,ascent12/sway,4e554c4c/sway,colemickens/sway,colemickens/sway,sleep-walker/sway,ascent12/sway,SirCmpwn/sway,crondog/sway,1ace/sway,mikkeloscar/sway,4e554c4c/sway,taiyu-len/sway,colemickens/sway,ascent12/sway,ptMuta/sway,mikkeloscar/sway,taiyu-len/sway,1ace/sway