Fixed apache listening on port 80 by default

The condition was inverted. It should be enabled by default unless the class to
disable it is defined.

Ticket: ENT-10672
Changelog: Title
(cherry picked from commit 19f113c)

cfe_internal/enterprise/templates/httpd.conf.mustache

@@ -5,7 +5,7 @@ ServerSignature Off
 ServerTokens ProductOnly
 ServerName {{{vars.sys.fqhost}}}
 ServerRoot "{{{vars.sys.workdir}}}/httpd"
-{{#classes.cfe_enterprise_disable_plain_http}}
+{{^classes.cfe_enterprise_disable_plain_http}}
 # ENT-10411
 Listen 80
 {{/classes.cfe_enterprise_disable_plain_http}}