(maybe) Remove OpenFL dependency on running the tools

When calling openfl-tools and openfl is not installed, it throws a (silent, I think) error, but the command line tools don't appear to be using the openfl haxelib code, only in the getVersion function.

This change moves the dependency to only trigger when called with openfl project flags, and only inside the getVersion function where it is actually used.

BUT. This doesn't seem to change anything and I can't call rebuild without installing openfl.
BUT. This is clearer anyway for what was there.