[master] Refactor reclimit system test

4823.	[test]		Refactor reclimit system test to improve its
			reliability and speed. [RT #46632]

bin/tests/system/reclimit/prereq.sh

@@ -9,6 +9,20 @@
 SYSTEMTESTTOP=..
 . $SYSTEMTESTTOP/conf.sh
 
+if $PERL -e 'use Net::DNS;' 2>/dev/null
+then
+    if $PERL -e 'use Net::DNS; die if ($Net::DNS::VERSION <= 0.78);' 2>/dev/null
+    then
+        :
+    else
+        echo "I:Net::DNS versions up to 0.78 have a bug that causes this test to fail: please update." >&2
+        exit 1
+    fi
+else
+    echo "I:This test requires the Net::DNS library." >&2
+    exit 1
+fi
+
 if $PERL -e 'use Net::DNS::Nameserver;' 2>/dev/null
 then
     :