Forwarding a mail message shows the attachment warning

[uli-heller]

I've just forwarded a mail message I received a couple of minutes ago. The message is written in German and

• it contains the attachment trigger word (German: "anbei", meaning "attached")
• it does not contain an attachment

Trying to forward this message triggers the attachment warning:

I don't think you should get an attachment warning in this situation. When forwarding a mail message, you should get an attachment warning only if you enter additional text and if this text contains attachment trigger words (= my personal opinion).

I'm using roundcube-1.3.0.

[alecpl]

Similar to #5045, but this one should be simpler to implement.