fixup! generic_mysql: shorter delays before retries

there was a mistake in 2de4c80f, we
should sleep for the min duration of these two

slapos/recipe/generic_mysql/mysql.py

@@ -43,7 +43,7 @@ def updateMysql(mysql_upgrade_binary, mysql_binary, mysql_script_file):
         break
       print 'SlapOS initialisation script succesfully applied on database.'
       return
-    sleep = max(sleep+1, 30)
+    sleep = min(sleep+1, 30)
     print 'Sleeping for %ss and retrying' % sleep
     sys.stdout.flush()
     sys.stderr.flush()

[Jérome Perrin]

https://nexedijs.erp5.net/#/test_result_module/20200720-7786A55B/6 failed with

2020-07-20 06:40:26 slapos[13862] INFO Finished computer partitions.
2020-07-20 06:40:26 slapos[13862] INFO ================================================================================
2020-07-20 06:40:26 slapos[13862] INFO Error with promises for the following partitions:
2020-07-20 06:40:26 slapos[13862] INFO   m0[mariadb]: Promise 'mariadb.py' failed with output: ERROR '"/data/slappart11_testnode/dcg/inst/test0-0/tmp/inst/m0/bin/mysql"  --execute \';\'  --host="10.0.12.198" --port="3306" --user="user" --password="insecure"' run with failure, output: "ERROR 1130 (HY000): Host '10.0.12.198' is not allowed to connect to this MariaDB server\n"

in snapshot, we have erp5/test.test_mariadb.TestMroonga.setUpClass/inst/m0/.m0_mariadb_update.log

Command '/data/slappart11_testnode/dcg/inst/test0-0/tmp/inst/m0/bin/mysql_upgrade' failed with result:
Version check failed. Got the following error when calling the 'mysql' command line client
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/data/slappart11_testnode/dcg/inst/test0-0/tmp/inst/m0/var/run/m' (2)
FATAL ERROR: Upgrade failed

Sleeping for 30s and retrying

it was not supposed to sleep 30s

I looked at history of erp5 test on on software release, it does not seem to happen often, but it was anyway incorrect.