显式空指针问题修复

cf-framework/cf-spring-boot-starter-mybatis/src/main/java/com/cf/imes/framework/mybatis/config/ChenfengMybatisAutoConfiguration.java

@@ -72,7 +72,7 @@ public class ChenfengMybatisAutoConfiguration {
             }
         }
         // 找不到合适的 IKeyGenerator 实现类
-        throw new IllegalArgumentException(CharSequenceUtil.format("DbType{} 找不到合适的 IKeyGenerator 实现类", dbType));
+        throw new IllegalArgumentException("DbType为空");
     }
 
 }