Remove doc reference disabling-default-password
Remove doc reference disabling-default-password

This section has been removed from setting-up-authentication. This
commit removes a reference to this section that no longer exists.

Original commit: elastic/x-pack-elasticsearch@43aa0077f91fee153b7d05526ca0e924d985a72b

nknize/elasticsearch,vroyer/elassandra,gingerwizard/elasticsearch,gfyoung/elasticsearch,gingerwizard/elasticsearch,robin13/elasticsearch,scorpionvicky/elasticsearch,GlenRSmith/elasticsearch,robin13/elasticsearch,strapdata/elassandra,coding0011/elasticsearch,HonzaKral/elasticsearch,nknize/elasticsearch,vroyer/elassandra,coding0011/elasticsearch,robin13/elasticsearch,uschindler/elasticsearch,strapdata/elassandra,vroyer/elassandra,gfyoung/elasticsearch,gfyoung/elasticsearch,gingerwizard/elasticsearch,coding0011/elasticsearch,uschindler/elasticsearch,HonzaKral/elasticsearch,gingerwizard/elasticsearch,nknize/elasticsearch,HonzaKral/elasticsearch,scorpionvicky/elasticsearch,uschindler/elasticsearch,scorpionvicky/elasticsearch,strapdata/elassandra,scorpionvicky/elasticsearch,strapdata/elassandra,nknize/elasticsearch,strapdata/elassandra,HonzaKral/elasticsearch,uschindler/elasticsearch,robin13/elasticsearch,coding0011/elasticsearch,GlenRSmith/elasticsearch,gfyoung/elasticsearch,coding0011/elasticsearch,gingerwizard/elasticsearch,GlenRSmith/elasticsearch,scorpionvicky/elasticsearch,nknize/elasticsearch,gfyoung/elasticsearch,gingerwizard/elasticsearch,robin13/elasticsearch,gingerwizard/elasticsearch,GlenRSmith/elasticsearch,uschindler/elasticsearch,GlenRSmith/elasticsearch