Remove or remove and re-write or ask to the copyright holder of the file inet_aton.c (guile-1.8.7/libguile/) to remove the 3º clause.
UCB and the BSDs have been dropping the advertising clause. inet_ntoa sources are available from NetBSD with a 3-clause license, but it's perhaps more complex than you want. If the copyright holder is Regents of the University of California, then you can perhaps use their published letter dropping the advertising clause on all of their works: ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
pgpvzRs0MW9yR.pgp
Description: PGP signature