(ITS#8874) --with-fetch incorrectly links libcom_err

[quanah@openldap.org]

Full_Name: Quanah Gibson-Mount
Version: 2.4.46
OS: FreeBSD 11
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (47.208.148.239)


When building OpenLDAP on FreeBSD where the fetch library is available, slapd
picks up a dependency on libcom_err which shouldn't exist.

This comes in from lines 934 and 944 of build/openldap.m4:
 934 LIBS="-lfetch -lcom_err $LIBS"
 944     ol_link_fetch="-lfetch -lcom_err"

These should be updated appropriately and configure regenerated