[mariadb] Improve python3 compatibility

Decode byte sequence into string before printing log.

Change-Id: Icd61a1373f5c62afda0558dfadc2add9138cff6d

mariadb/Chart.yaml

@@ -15,7 +15,7 @@ apiVersion: v1
 appVersion: v10.6.7
 description: OpenStack-Helm MariaDB
 name: mariadb
-version: 0.2.54
+version: 0.2.55
 home: https://mariadb.com/kb/en/
 icon: http://badges.mariadb.org/mariadb-badge-180x60.png
 sources:

mariadb/templates/bin/_start.py.tpl

@@ -159,7 +159,7 @@ def run_cmd_with_logging(popenargs,
         ready_to_read = select.select([child.stdout, child.stderr], [], [],
                                       1000)[0]
         for io in ready_to_read:
-            line = io.readline()
+            line = io.readline().decode()
             logger.log(log_level[io], line[:-1])
 
     while child.poll(

releasenotes/notes/mariadb.yaml

@@ -70,4 +70,5 @@ mariadb:
   - 0.2.52 Added SSL support to cluster-wait job
   - 0.2.53 Use constant for mysql binary name
   - 0.2.54 Improve leader election on cold start
+  - 0.2.55 Improve python3 compatibility
 ...