Switch all calls to open() to explicitly open for read

cluster-webmin/edit_mod.cgi

@@ -85,7 +85,7 @@ if ($type eq 'mod') {
 		print $text{'edit_osall'};
 		}
 	else {
-		open(OSLIST, "$root_directory/os_list.txt");
+		open(OSLIST, "<$root_directory/os_list.txt");
 		while(<OSLIST>) {
 			chop;
 			if (/^([^\t]+)\t+([^\t]+)\t+(\S+)\t+(\S+)\t*(.*)$/) {

cluster-webmin/install.cgi

@@ -63,7 +63,7 @@ elsif ($in{source} == 2) {
 $grant = $in{'grant'} ? undef : [ split(/\s+/, $in{'grantto'}) ];
 
 # Check validity
-open(MFILE, $pfile);
+open(MFILE, "<$pfile");
 read(MFILE, $two, 2);
 close(MFILE);
 if ($two eq "\037\235") {

cluster-webmin/upgrade.cgi

@@ -200,7 +200,7 @@ else {
 	}
 
 # gunzip the file if needed
-open(FILE, $file);
+open(FILE, "<$file");
 read(FILE, $two, 2);
 close(FILE);
 if ($two eq "\037\213") {