Add update script to add DecodeEnabled

db/zm_update-1.35.16.sql

@@ -0,0 +1,12 @@
+
+SET @s = (SELECT IF(
+    (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS WHERE table_schema = DATABASE()
+      AND table_name = 'Monitors'
+      AND column_name = 'DecodingEnabled'
+    ) > 0,
+    "SELECT 'Column DecodingEnabled already exists in Monitors'",
+    "ALTER TABLE Monitors ADD `DecodingEnabled` tinyint(3) unsigned NOT NULL default '1' AFTER `Enabled`"
+    ));
+
+PREPARE stmt FROM @s;
+EXECUTE stmt;