smb.conf: Avoid setting duplicate/ignored options

[anoopcs9]

• 'kernel share modes' is disabled by default.

  This parameter defaults to no. Setting it to yes requires a file system module that supports file system sharemodes, otherwise attempts to access files will fail with a sharing violation.

  Default: kernel share modes = no

• 'store dos attributes', which is set by default, assumes 'map archive' to be disabled.

  When this parameter is set it will override the parameters map hidden, map system, map archive and map readonly and they will behave as if they were set to off.

  Default: store dos attributes = yes