tripwire: Fix path to nano in default twcfg.txt

Nano is installed under /usr/bin/, not /bin/.

Installed Tripwire on a Fido image and successfully ran
`tripwire --update` to invoke text editor.

Signed-off-by: Haris Okanovic <haris.okanovic@ni.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

recipes-security/tripwire/files/twcfg.txt

@@ -4,7 +4,7 @@ DBFILE                 =/var/lib/tripwire/$(HOSTNAME).twd
 REPORTFILE             =/var/lib/tripwire/report/$(HOSTNAME)-$(DATE).twr
 SITEKEYFILE            =/etc/tripwire/site.key
 LOCALKEYFILE           =/etc/tripwire/$(HOSTNAME)-local.key
-EDITOR                 =/bin/nano
+EDITOR                 =/usr/bin/nano
 LATEPROMPTING          =false
 LOOSEDIRECTORYCHECKING =false
 MAILNOVIOLATIONS       =true