[patch]maat not handle regex string

test/regex_expr.conf

@@ -92,6 +92,20 @@
                     "pattern": "123^abc"
                 }
             ]
+        },
+        {
+
+            "rule_id": 306,
+            "pattern_num": 1,
+            "patterns": [
+                {
+                    "pattern_type": "regex",
+                    "match_method": "sub",
+                    "case_sensitive": "no",
+                    "is_hexbin": "no",
+                    "pattern": "^[1-9]\d{5}(18|19|([23]\d))\d{2}((0[1-9])|(10|11|12))(([0-2][1-9])|10|20|30|31)\d{3}[0-9Xx]$"
+                }
+            ]
         }
     ]
 }