[Minor]ignore all config files in conf

Some config files in ```conf``` should ignore, such as
        conf/fairscheduler.xml
        conf/hive-log4j.properties
        conf/metrics.properties
...
So ignore all ```sh```/```properties```/```conf```/```xml``` files

Author: wangfei <wangfei1@huawei.com>

Closes #2395 from scwf/patch-2 and squashes the following commits:

3dc53f2 [wangfei] duplicate ```conf/*.conf```
3c2986f [wangfei] ignore all config files