`!rss template 123` without the template

[opk12]

!rss template 858

Template for feed ID 858 updated. Sample notification:

I did this while playing around with the bot, but it may happen if failing to press Ctrl + V before mindlessly pressing Enter.

• The reply should make it clear what has happened - did I reset the template to the default or to ""?
• The command should print the current template ([feature] Print the current template #55), or reset to the default, or fail.

[miguelrdev]

See: #55 (comment)