runtests: fix an incorrect comment about the ld_preload feature

Follow-up to 1f631864

Ref: #10818

diff --git a/tests/runtests.pl b/tests/runtests.pl
index 6d4d4757ac6bebcdee755fe2cc608003d5ea755f..53a4b72e20076d57b1fb745c78bb3d17e2d56def 100755 (executable)
--- a/tests/runtests.pl
+++ b/tests/runtests.pl
@@ -3056,7 +3056,7 @@ sub checksystemfeatures {
         close($conf);
     }
 
-    # disable this feature unless debug mode is also enabled
+    # allow this feature only if debug mode is disabled
     $feature{"ld_preload"} = $feature{"ld_preload"} && !$feature{"debug"};
 
     if($feature{"ipv6"}) {