[Reportbug-maint] Bug#782319: reportbug: Attribute expanduser missing from python and fail to send bugs

[Corcodel Marian]

Hi
Error is

Traceback (most recent call last):
   File "/usr/bin/reportbug", line 2211, in <module>
     main()
   File "/usr/bin/reportbug", line 1081, in main
     return iface.user_interface()
   File "/usr/bin/reportbug", line 2203, in user_interface
     self.options.envelopefrom)
   File "/usr/lib/python2.7/dist-packages/reportbug/submit.py", line 
316, in send_report
     msgname = os.path.expanduser(outfile) or ('/var/tmp/%s.bug' % package)
   File "/usr/lib/python2.7/posixpath.py", line 261, in expanduser
     if not path.startswith('~'):
AttributeError: 'NoneType' object has no attribute 'startswith'

I not have MTA installed  on machine and when put on configuration:
smtphost marian1000.go.ro:25
all is ok.
On this want to exit wo errors when missing smtphost variable.
App reportbug is unable to detect mail server and work with def 
configuration only when MTA is on same machine with app reportbug.
Cheers