cubicweb #978144 exception with view send-email if empty subject [resolved]

Forgetting to set a subject in the send-email form raised an exception and the content was lost:

...
File "/usr/lib/python2.5/site-packages/cubicweb/mail.py", line 88, in format_mail
  subject = subject.splitlines()[0]
IndexError: list index out of range
prioritynormal
typebug
done in3.8.3
load0.100
load left0.000
closed by<not specified>