[avocado] Add cleaner test for #4154

Closes: #4212

Signed-off-by: Pavel Moravec <pmoravec@redhat.com>

Author: pmoravec

tests/cleaner_tests/ipv6_test/sos-test-ipv6.txt

@@ -2,6 +2,8 @@ This is a test file for ipv6 address obfuscation.
 
 This address should be obfuscated
 GOOD_IP=3000:505f:505f:505f:505f:505f:505f:505f
+As well as with trailing ':':
+GOOD_IP=3000:505f:505f:505f:505f:505f:505f:505f:
 
 This address should not get sos stuck
 BAD_IP=505f:505f:505f:505f:505f:505f:505f:505f