ftpserver.pl: Corrected invalid argument check in POP3 TOP handler

...which was accidentally introduced in commit 4d6ef6297ae9b6.

diff --git a/tests/ftpserver.pl b/tests/ftpserver.pl
index 075e02e..78e50c6 100755 (executable)
--- a/tests/ftpserver.pl
+++ b/tests/ftpserver.pl
@@ -1584,7 +1584,7 @@ sub TOP_pop3 {
     if (!grep /^TOP$/, @capabilities) {
         sendcontrol "-ERR Unrecognized command\r\n";
     }
-    elsif ((!$msg) || (!$lines)) {
+    elsif (($msg eq "") || ($lines eq "")) {
         sendcontrol "-ERR Protocol error\r\n";
     }
     else {