TT#56053 Fix using of boolean SKIP* variables

The name of the variables SKIP_DNS_CHECK_TEST and
SKIP_STRICT_HOSTNAME_TEST so if they are 'true' the check should be
skipped. But in code it has direct branching, if the variable true -
run the test.

So add the negation to checks of these variables.

Change-Id: Iaf1e252dbb30cd2dc624db71742fa2cee8edb888

templates/800_network-hostname.yaml.tt2

@@ -15,7 +15,7 @@ command:
   hostname:
     exit-status: 0
 
-{{if .Vars.SKIP_STRICT_HOSTNAME_TEST}}
+{{if not .Vars.SKIP_STRICT_HOSTNAME_TEST}}
   hostname:
     exit-status: 0
     stdout:

templates/goss.yaml.tt2

@@ -24,7 +24,7 @@ gossfile:
   610_kernel-sysctl-params.yaml: {}
   615_kernel-modules.yaml: {}
   800_network-hostname.yaml: {}
-{{if .Vars.SKIP_DNS_CHECK_TEST}}
+{{if not .Vars.SKIP_DNS_CHECK_TEST}}
   810_network-dns-debian.yaml: {}
 [%   IF general.ngcp_type == 'spce' -%]
   811_network-dns-ngcp-ce.yaml: {}