Add more log/tap rotation tests

Add more tests to the dnstap system test to roll with different values.
Touch some files to make sure the number of existing files exceed the
number that we want to keep.

Add a test to the logfileconfig system test for the increment suffix.

bin/tests/system/logfileconfig/clean.sh

@@ -31,6 +31,8 @@ rm -f ns1/named_vers
 rm -f ns1/named_vers.*
 rm -f ns1/named_ts
 rm -f ns1/named_ts.*
+rm -f ns1/named_inc
+rm -f ns1/named_inc.*
 rm -f ns1/named_unlimited
 rm -f ns1/named_unlimited.*
 rm -f ns*/managed-keys.bind*