fix the bug findAndCountAll not working on postgresql.

copy `where` array, avoid changed by internal.

lib/dialects/postgres/query-generator.js

@@ -547,7 +547,7 @@ module.exports = (function() {
         result = smth
       }
       else if (Array.isArray(smth)) {
-        result = Utils.format(smth, "postgres")
+        result = Utils.format(smth.slice(0), "postgres")
       }
 
       return result