[TD-1986]<fix>: default days to 10 instead of 2

TD-1982

Merge pull request #4212 from taosdata/dependabot/maven/tests/examples/JDBC/connectionPools/com.mchange-c3p0-0.9.5.4

Bump c3p0 from 0.9.5.2 to 0.9.5.4 in /tests/examples/JDBC/connectionPools

[update]

Bumps [c3p0](https://github.com/swaldman/c3p0) from 0.9.5.2 to 0.9.5.4.
- [Release notes](https://github.com/swaldman/c3p0/releases)
- [Commits](https://github.com/swaldman/c3p0/compare/c3p0-0.9.5.2...c3p0-0.9.5.4)
Signed-off-by: Ndependabot[bot] <support@github.com>

[TD-2084]<hotfix>: invalid read when close TSDB

Feature/td 2052

Update TAOS SQL-ch.md

fix a mistake

Feature/wal

[TD-2063]<fix> not free result resource in async callback function

[TD-2055]<fix>: core dump in wildcard query

[TD-1998]<fix>: cannot parse valid sql statement

[TD-2062]modify taos website

add async write

[TD-1447] <test> add test case for lowa

[TD-1896]<fix>: Wal data may be lost when the system crashes