Fix resetting a config with a non default target name (#15448)
Fix resetting a config with a non default target name (#15448)

mc admin config reset <alias> notify_webhook:something was not working
properly.

The reason is that GetSubSys() was not calculating the target
name properly because it is quitting early when the number of config
inputs ('notify_webhook:something' in this case) is equal to 1.

This commit will make the code calculates always calculate the target
name if found.

donatello/minio,minio/minio,balamurugana/minio,krisis/minio,vadmeste/minio,balamurugana/minio,vadmeste/minio,minio/minio,krisis/minio,donatello/minio