fix mysql connect error in travis ci

[amyangfei]

CI on travis always meets the following error recently:

$ sudo mysql -e "use mysql; update user set authentication_string=PASSWORD('') where User='root'; update user set plugin='mysql_native_password';FLUSH PRIVILEGES;"
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)
The command "sudo mysql -e "use mysql; update user set authentication_string=PASSWORD('') where User='root'; update user set plugin='mysql_native_password';FLUSH PRIVILEGES;"" failed and exited with 1 during .

ref: https://travis-ci.community/t/cant-connect-to-local-mysql-server-through-socket-var-run-mysqld-mysqld-sock/3414/2

• add service mysql to fix this error
• as SSL/TLS is not enabled by default, we run sudo mysql_ssl_rsa_setup --uid=mysql to enable it
• fix a data race in canal package

[siddontang]

oh, CI failed, seem we meet a data race problem.

/cc @GregoryIan

[siddontang]

can you fix it? @amyangfei

[amyangfei]

have fixed the data race and CI
PTAL @siddontang @GregoryIan