Properly check for null when checking system permissions.

guacamole/src/main/java/net/sourceforge/guacamole/net/basic/ConfigurationList.java

@@ -168,7 +168,7 @@ public class ConfigurationList extends AuthenticatingHttpServlet {
             xml.writeStartElement("configs");
             
             // Save config create permission attribute
-            if (hasConfigPermission(permissions, username,
+            if (permissions != null && hasConfigPermission(permissions, username,
                     SystemPermission.Type.CREATE))
                 xml.writeAttribute("create", "yes");
             

guacamole/src/main/java/net/sourceforge/guacamole/net/basic/UserList.java

@@ -152,7 +152,7 @@ public class UserList extends AuthenticatingHttpServlet {
             xml.writeStartElement("users");
             
             // Save user create permission attribute
-            if (hasUserPermission(permissions, username,
+            if (permissions != null && hasUserPermission(permissions, username,
                     SystemPermission.Type.CREATE))
                 xml.writeAttribute("create", "yes");