Try to resolve confusion in CVEs for xymon

We have to assume that the now set is correct. Former communication
involved those CVEs which were used as well by the maintainer in the
debian/changelog file. But upstream used different CVEs (possibly
typoed) in the announce in https://lists.xymon.com/archive/2019-July/046570.html

The correct set of CVEs should be thus

       - CVE-2019-13451: service overflows histlogfn in history.c.
       - CVE-2019-13452: service overflows histlogfn in reportlog.c.
       - CVE-2019-13273: srdb overflows dbfn in csvinfo.c.
       - CVE-2019-13274: reflected XSS in csvinfo.c.
       - CVE-2019-13455: htmlquoted(hostname) overflows msgline in
         acknowledge.c.
       - CVE-2019-13484: htmlquoted(xymondreq) overflows errtxt appfeed.c.
       - CVE-2019-13485: hostname overflows selfurl in history.c.
       - CVE-2019-13486: htmlquoted(xymondreq) overflows errtxt in
         svcstatus.c.