[monitoring-plugins] plugins/t/check_dns.t: Fix Perl warning

[Holger Weiss]

 Module: monitoring-plugins
 Branch: master
 Commit: c5a64eeef8340ff39fafb21878d92139b4c1fb73
 Author: Holger Weiss <holger at zedat.fu-berlin.de>
   Date: Mon Jul 21 13:59:22 2014 +0200
    URL: https://www.monitoring-plugins.org/repositories/monitoring-plugins/commit/?id=c5a64ee

plugins/t/check_dns.t: Fix Perl warning

Perl said: "Unrecognized escape \d passed through at ./t/check_dns.t
line 57."

---

 plugins/t/check_dns.t | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/plugins/t/check_dns.t b/plugins/t/check_dns.t
index 4ff553f..b885880 100644
--- a/plugins/t/check_dns.t
+++ b/plugins/t/check_dns.t
@@ -54,7 +54,7 @@ cmp_ok( $res->return_code, '==', 2, "Critical threshold passed");
 
 $res = NPTest->testCmd("./check_dns -H $hostname_valid -t 5 -w 0 -c 5");
 cmp_ok( $res->return_code, '==', 1, "Warning threshold passed");
-like( $res->output, "/\|time=[\d\.]+s;0.0*;5\.0*;0\.0*/", "Output performance data OK" );
+like( $res->output, '/\|time=[\d\.]+s;0.0*;5\.0*;0\.0*/', "Output performance data OK" );
 
 $res = NPTest->testCmd("./check_dns -H $hostname_invalid -t 1");
 cmp_ok( $res->return_code, '==', 2, "Invalid $hostname_invalid");