add mongodb initialization wait time parser

[Vanderln]

I'd like to add a configuration to set the wait time for the mongodb initialization. I'm currently using this plugin and I need it to wait a little longer for mongodb to initialize.

[mbanton]

Hello @Vanderln . Thanks for your interest and contribution.

But to do the merge with this project I suggest that you keep the name of the plugin and original credits and add your code snippet with the optional parameter (if not informed the parameter keep the old behavior 0.3 seconds).

So we can keep somete a plugin and avoid fragmentation. What do you think?