Take configuration file path from local variable

We used to load the configuration file from App, but moved it to a
separate file. By then options were an instance variable, and when we
moved it to a separate file we forgot to remove a reference to self.
This is an error that will be triggered by specifying a configuration
file on the command line, since self is not defined.

Take the path to the configuration file from the local options variable.

Signed-off-by: Marcus Karlsson <mk@acc.umu.se>