Close connection to LDAP server after calling authenticate user (#565)

Co-authored-by: Pavlo <pavlo@>

Author: vpp

lib/passport/index.js

@@ -52,6 +52,8 @@ function authenticate_user(args){
       .then(function(ldap_server){
 
       ldap_server.authenticate(email, password, function (err, u) {
+        ldap_server.close();
+
         if (err) {
           console.log("LDAP auth error: %s", err);
           return done(null, false);