use array check

Author: samsonasik

system/Database/Forge.php

@@ -704,9 +704,11 @@ public function addColumn(string $table, $field): bool
             return false;
         }
 
-        foreach ($sqls as $sql) {
-            if ($this->db->query($sql) === false) {
-                return false;
+        if (is_array($sqls)) {
+            foreach ($sqls as $sql) {
+                if ($this->db->query($sql) === false) {
+                    return false;
+                }
             }
         }