phosphor-ldap-conf: add support for anonymous bind

Add "bindpw <password>" entry into nslcd.conf file only
if given password is not null.

Change-Id: Ifa4a90c6fd41d5b36c62328dcf3e9bfc38dd0ebb
Signed-off-by: Nagaraju Goruganti <ngorugan@in.ibm.com>
diff --git a/phosphor-ldap-config/ldap_configuration.cpp b/phosphor-ldap-config/ldap_configuration.cpp
index e3b337d..c84927d 100644
--- a/phosphor-ldap-config/ldap_configuration.cpp
+++ b/phosphor-ldap-config/ldap_configuration.cpp
@@ -79,7 +79,11 @@
     confData << "uri " << lDAPServerURI() << "\n\n";
     confData << "base " << lDAPBaseDN() << "\n\n";
     confData << "binddn " << lDAPBindDN() << "\n";
-    confData << "bindpw " << lDAPBINDDNpassword() << "\n\n";
+    if (!lDAPBINDDNpassword().empty())
+    {
+        confData << "bindpw " << lDAPBINDDNpassword() << "\n";
+    }
+    confData << "\n";
     switch (lDAPSearchScope())
     {
         case ldap_base::Config::SearchScope::sub:
@@ -102,8 +106,9 @@
     }
     else
     {
-        confData << "ssl off\n\n";
+        confData << "ssl off\n";
     }
+    confData << "\n";
     if (lDAPType() == ldap_base::Config::Type::ActiveDirectory)
     {
         confData << "filter passwd (&(objectClass=user)(objectClass=person)"