[KYUUBI #433] [MINOR] Update conf template

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### _Why are the changes needed?_
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Put `kyuubi.frontend.bind.host` on Kyuubi conf template, it's more friendly for users who first try Kyuubi but struggling on binding to `127.0.0.1`, just like case #384

### _How was this patch tested?_
- [ ] Add some test cases that check the changes thoroughly including negative and positive cases if possible

- [ ] Add screenshots for manual tests if appropriate

- [ ] [Run test](https://kyuubi.readthedocs.io/en/latest/tools/testing.html#running-tests) locally before make a pull request

Closes #433 from pan3793/conf.

2e3f67e [Cheng Pan] [MINOR] Update conf template

Authored-by: Cheng Pan <379377944@qq.com>
Signed-off-by: Kent Yao <yao@apache.org>

conf/kyuubi-defaults.conf.template

@@ -19,6 +19,7 @@
 
 #
 # kyuubi.authentication           NONE
+# kyuubi.frontend.bind.host       localhost
 # kyuubi.frontend.bind.port       10009
 #