HPCC-10126 htpasswd Authentication Modify Users Issue

When HTPASSWD authentication is enabled, LDAP specific features such as
permissions, grouping,etc are not supported. This pull request adds a new
error message "LDAP Security manager is required for this feature. Please
 enable LDAP in the system configuration" that is now displayed any time
these features are selected

Signed-off-by: William Whitehead <william.whitehead@lexisnexis.com>
Merge pull request #4913 from RussWhitehead/htPwd

HPCC-10126 htpasswd Authentication Modify Users Issue

Reviewed-By: Gordon Smith <gordon.smith@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>