JNDI code for tomcat plugin throws exception on server auto restart during code change during development

When reading JNDI entries from config.groovy file for database connection information, the code removes the "type","auth","description" & "scope". Due to this, when the server restarts, it is not able to find the "type" attribute and throws IllegalArgumentException with message "Must supply a resource type for JNDI configuration"

I have changed to code (attached patch) so that it does not remove these attributes but just reads it so that consecutive server restarts can read them again. Please let me know if it looks good enough to push it.

This bug was injected by the fix done for #GRAILS-5521