configfile.c: Fixed Include'ing empty files.

configfile.c: Fixed Include'ing empty files.

When including empty files, a typo prevented that the "Include" child (of the
config parse tree) was removed correctly, leaving behind garbage which in turn
led to a segfault if the Include option was not the last element of the config
file.

Also, another Include option following the inclusion of an empty file used to
be ignored. This has been fixed as well.