changes getattr from settings to account for None values

[kbuilds]

This change makes it easier to configure the port and host settings from environment variables.

For example, I might set this up in my settings.py as:

LIVERELOAD_HOST = os.getenv("LIVERELOAD_HOST")
LIVERELOAD_PORT = os.getenv("LIVERELOAD_PORT")

This makes it so that developers on my team can specify these values in their environment variables. The default return value for getenv() when the variable is not found is None. This PR makes sure that a value of None in the settings.py file does not break this livereload system.

[kbuilds]

@tjwalch Is this project still active?

[tjwalch]

@kbuilds It has been sort of inactive for I while, I have been too busy with other stuff. I am however planning to give it a look, merge PR's and make a new release within the next week or so.

[kbuilds]

@tjwalch Let me know if you need some help. I have experience with Django and Tornado

[tjwalch]

@kbuilds Yes, I think this project could benefit from some more collaborators, if you are interested in that I can add you to the project.

[kbuilds]

@tjwalch Sure. I would be happy to help. I already have a fork, but feel free to add me as a maintainer or contributor. Whatever is easier. Maybe we can chat about what kinds of features you are trying to add here.