test/ssl_test.tmpl: make it work with elderly perl.

Reviewed-by: NRich Salz <rsalz@openssl.org>

test/ssl_test.tmpl

@@ -90,35 +90,35 @@ client = {-$testname-}-client{-
 
     if ($server{"extra"}) {
         $OUT .= "\n[$testname-server-extra]\n";
-        foreach my $key (sort keys $server{"extra"}) {
+        foreach my $key (sort keys %{$server{"extra"}}) {
             $OUT .= qq{$key} . " = " . qq{$server{"extra"}{$key}\n}
 	    	 if defined $server{"extra"}{$key};
         }
     }
     if (%server2 && $server2{"extra"}) {
         $OUT .= "\n[$testname-server2-extra]\n";
-        foreach my $key (sort keys $server2{"extra"}) {
+        foreach my $key (sort keys %{$server2{"extra"}}) {
             $OUT .= qq{$key} . " = " . qq{$server2{"extra"}{$key}\n}
 	    	 if defined $server2{"extra"}{$key};
         }
     }
    if (%resume_server && $resume_server{"extra"}) {
         $OUT .= "\n[$testname-resume-server-extra]\n";
-        foreach my $key (sort keys $resume_server{"extra"}) {
+        foreach my $key (sort keys %{$resume_server{"extra"}}) {
             $OUT .= qq{$key} . " = " . qq{$resume_server{"extra"}{$key}\n}
 	    	 if defined $resume_server{"extra"}{$key};
         }
     }
    if ($client{"extra"}) {
         $OUT .= "\n[$testname-client-extra]\n";
-        foreach my $key (sort keys $client{"extra"}) {
+        foreach my $key (sort keys %{$client{"extra"}}) {
             $OUT .= qq{$key} . " = " . qq{$client{"extra"}{$key}\n}
 	    	 if defined $client{"extra"}{$key};
         }
    }
    if (%resume_client && $resume_client{"extra"}) {
         $OUT .= "\n[$testname-resume-client-extra]\n";
-        foreach my $key (sort keys $resume_client{"extra"}) {
+        foreach my $key (sort keys %{$resume_client{"extra"}}) {
             $OUT .= qq{$key} . " = " . qq{$resume_client{"extra"}{$key}\n}
 	    	 if defined $resume_client{"extra"}{$key};
         }