update default samplers

modules/sd_samplers.py

@@ -6,7 +6,7 @@ all_samplers = [
     *sd_samplers_compvis.samplers_data_compvis,
 ]
 all_samplers_map = {x.name: x for x in all_samplers}
-samplers = []
+samplers = ['PLMS', 'UniPC'] # set default to keep some extensions happy
 samplers_for_img2img = []
 samplers_map = {}