Reload init when calling ledger-init-load-init-file again.

When the ledger-init-load-init-file was called again, it used to parse ledger
init file, and to throw away the result. No you can use it to load this file
again when you have change something in it.
Merge pull request #218 from vanicat/t/reload-init

Reload init when calling ledger-init-load-init-file again.

I don't know why I missed that before.  This is how it is supposed to work. Thanks.