Defer loading so-long until needed

[abougouffa]

This package is useful when enabled at startup. However, we might not need to use so-long-predicate until a file has been open. So, lets defer loading the so-long package.

This is useful for users who want to optimize Emacs' startup time

[jcs090218]

Can you resolve the compile warning?

guard-lf.el:92:16: Warning: reference to free variable ‘so-long-predicate’

[abougouffa]

Thanks for the quick reply @jcs090218

Can you resolve the compile warning?
Done

[jcs090218]

LGTM, Thank you! :)