HPCC-11589 Configmgr tooltip needs better explaination of ldap username fields

Current tooltip for LDAP systemUser and systemCommonName is confusing. This
fix clears that up by explaining the actual meaning

Signed-off-by: William Whitehead <william.whitehead@lexisnexis.com>
Merge pull request #5992 from RussWhitehead/toolTip

HPCC-11589 Configmgr tooltip needs better explaination of ldap username ...

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>