rkhunter update fails "Invalid WEB_CMD configuration option"

I found that rkhunter v1.4.2 on Debian stretch and after upgrading to rkhunter v1.4.4 on Ubuntu 17.10 have a strange problem that I cannot perform an update. In both instances I receive the following:

$ sudo rkhunter --versioncheck
Invalid WEB_CMD configuration option: Relative pathname: "/bin/false"
$ sudo rkhunter --update
Invalid WEB_CMD configuration option: Relative pathname: "/bin/false"

A search around the net shows that this was an intentional change in the last point release which included an update for rkhunter as well. It is due to #866677.

In searching for a resolution, I first attempted to remove /bin/false from the WEB_CMD in the rkhunter.conf but this resulted in another issue where updates would fail:

$ sudo rkhunter --update
[ Rootkit Hunter version 1.4.2 ]

Checking rkhunter data files...
  Checking file mirrors.dat                   [ Skipped ]
  Checking file programs_bad.dat              [ Update failed ]
  Checking file backdoorports.dat             [ Update failed ]
  Checking file suspscan.dat                  [ Update failed ]
  Checking file i18n versions                 [ Update failed ]

In digging a little into the rkhunter source (https://sourceforge.net/projects/rkhunter/files/) and an older configuration file on my system I found the following differences:

$ diff /etc/rkhunter.conf /etc/rkhunter.conf.dpkg-dist
108c107
< UPDATE_MIRRORS=0
---
> #UPDATE_MIRRORS=1
124c122
< MIRRORS_MODE=1
---
> #MIRRORS_MODE=0
325c323
< WEB_CMD="/bin/false"
---
> WEB_CMD=""

Therefore, all I needed to do is to replace the following entries in the /etc/rkhunter.conf file

Old valueNew value
UPDATE_MIRRORS=0 UPDATE_MIRRORS=1
MIRRORS_MODE=1 MIRRORS_MODE=0
WEB_CMD="/bin/false" WEB_CMD=""

After the changes, running rkhunter updates are now successful:

$ sudo rkhunter --versioncheck
[ Rootkit Hunter version 1.4.2 ]

Checking rkhunter version...
  This version  : 1.4.2
  Latest version: 1.4.2
$ sudo rkhunter --update
[ Rootkit Hunter version 1.4.2 ]

Checking rkhunter data files...
  Checking file mirrors.dat                   [ No update ]
  Checking file programs_bad.dat              [ No update ]
  Checking file backdoorports.dat             [ No update ]
  Checking file suspscan.dat                  [ No update ]
  Checking file i18n versions                 [ Skipped ]

This fix also works for rkhunter v1.4.4