[monitoring-plugins] Fix unknown escape sequence error output

[waja]

    Module: monitoring-plugins
    Branch: master
    Commit: 28553e8d1cc56de12e4c9f7705a92f0e0e86d9d9
    Author: RincewindsHat <12514511+RincewindsHat at users.noreply.github.com>
 Committer: waja <waja at users.noreply.github.com>
      Date: Mon Dec 19 17:15:49 2022 +0100
       URL: https://www.monitoring-plugins.org/repositories/monitoring-plugins/commit/?id=28553e8

Fix unknown escape sequence error output

---

 plugins/check_apt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/plugins/check_apt.c b/plugins/check_apt.c
index d7be575..f70fec1 100644
--- a/plugins/check_apt.c
+++ b/plugins/check_apt.c
@@ -530,7 +530,7 @@ print_help (void)
   printf ("    %s\n", _("this REGEXP, the plugin will return CRITICAL status.  Can be specified"));
   printf ("    %s\n", _("multiple times like above.  Default is a regexp matching security"));
   printf ("    %s\n", _("upgrades for Debian and Ubuntu:"));
-  printf ("    \t\%s\n", SECURITY_RE);
+  printf ("    \t%s\n", SECURITY_RE);
   printf ("    %s\n", _("Note that the package must first match the include list before its"));
   printf ("    %s\n", _("information is compared against the critical list."));
   printf (" %s\n", "-o, --only-critical");