Description of problem:
Current jinja template (timemaster.conf.j2) is having below.

{% for domain, nic_list in ptp_dict.items() %}
[ptp_domain {{ domain }}]
interfaces {% for nic in nic_list %}
{{ nic }}{% if not loop.last %},{% endif %}
{% endfor %}

{% endfor %}

Due to this, when below is passed via THT,
PTPInterfaces: '0:eno1,0:eno2'

results into

[ptp_domain 0]
interfaces eno1,eno2

timemaster service fails with this message.

[root@computedpdk-0 heat-admin]# systemctl status timemaster
● timemaster.service - Synchronize system clock to NTP and PTP time sources
   Loaded: loaded (/usr/lib/systemd/system/timemaster.service; enabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Mon 2021-07-05 12:12:05 UTC; 4s ago
  Process: 169838 ExecStart=/usr/sbin/timemaster -f /etc/timemaster.conf (code=exited, status=1/FAILURE)
 Main PID: 169838 (code=exited, status=1/FAILURE)

Jul 05 12:12:05 computedpdk-0 systemd[1]: timemaster.service: Succeeded.
Jul 05 12:12:05 computedpdk-0 systemd[1]: Stopped Synchronize system clock to NTP and PTP time sources.
Jul 05 12:12:05 computedpdk-0 systemd[1]: Started Synchronize system clock to NTP and PTP time sources.
Jul 05 12:12:05 computedpdk-0 timemaster[169838]: timemaster[532409.195]: ioctl SIOCETHTOOL failed: No such device
Jul 05 12:12:05 computedpdk-0 timemaster[169838]: timemaster[532409.195]: failed to get time stamping info for eno1,eno2 <<<<<<<<<<<<<<<<<<<<
Jul 05 12:12:05 computedpdk-0 systemd[1]: timemaster.service: Main process exited, code=exited, status=1/FAILURE
Jul 05 12:12:05 computedpdk-0 systemd[1]: timemaster.service: Failed with result 'exit-code'.

Version-Release number of selected component (if applicable):
16.2

How reproducible:
Always

Steps to Reproduce:
- Perform deployment with above mentioned PTPInterface value.

Expected results:
Ideally, we should have

[ptp_domain 0]
interfaces eno1 eno2 <<<<No ","

To start timemaster service successfully.

Actual result:
Failed timemaster service on the node.

We need to replace "," with "" in order to generate working template.

Additional info: