### What changes were proposed in this pull request?
30s for fetch timeout is too short and easy to exceed. This PR increases the default value to 600s.
### Why are the changes needed?
When I was testing 3T TPCDS with three workers, I encountered fetch timeout:
```
23/06/21 16:46:41,771 INFO [fetch-server-11-7] FetchHandler: Sending chunk 28856864163, 1, 0, 2147483647
...
23/06/21 16:47:16,870 INFO [fetch-server-11-7] FetchHandler: Sent chunk 28856864163, 1, 0, 2147483647
```
And I remember from some users' monitoring, the max fetch time can reach several minutes on heavy load without error.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
Manual test.
Closes#1618 from waitinfuture/709.
Authored-by: zky.zhoukeyong <zky.zhoukeyong@alibaba-inc.com>
Signed-off-by: zky.zhoukeyong <zky.zhoukeyong@alibaba-inc.com>
e2eeafd4bf