Restore MITM functionality

Prior change 1158463 did not handle a fallthough case, breaking
MITM detection. With this change:

* MITM detection notification is restored instead of failing
  the print job
* IPPS is preferred if only IPP is found during capability check

Test: Print to a printer, change its certificate, print again
Fixes: 154046844
Change-Id: If51aafb1276c45855c613549b240dadd08fdf611
Signed-off-by: Glade Diviney <mopriadevteam@gmail.com>
3 files changed