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()