Text rendering does not work for e-mails (no new lines) received in Zammad

[Bozo0511]

Infos:

This works on Zammad 4.0 like intended.

• Used Zammad version: 5.0.x
• Installation method (source, package, ..): N/A
• Operating system: N/A
• Database + version: N/A
• Elasticsearch version: N/A
• Browser + version: N/A
• Ticket number: 1096288

Expected behavior:

When an e-mail is received, Zammad should render the text like it is in the e-mail 

Actual behavior:

When an e-mail is received Zammad does not render the text. The whole content of the mail is displayed as in a continuous flow text.

Steps to reproduce the behavior:

Send the test mail attached to the issue, to the Zammad inbox
Test 1.zip

Yes I'm sure this is a bug and no feature request or a general question.

[martini]

Regression of f50016b#diff-7a3f591cbfde2c170f932b83646c12bbc5db4f65687358c6c03f625becadb2fd