bad feedback after failure of opening database

[Karl-Philipp Richter]

After an unknown failure of opening a database fail, the UI displays a dialog with the content "Indexing failed" which is inacceptably bad feedback and

    Indexing failed
    :2:../rcldb/rcldb.cpp:689:Db::open: exception while opening [/home/richter/.recoll/xapiandb]: Error opening table `/home/richter/.recoll/xapiandb/record.':
    Bad base file format 1 in /home/richter/.recoll/xapiandb/record.baseA
    Bad base file format 1 in /home/richter/.recoll/xapiandb/record.baseB

is logged which leaves the use few more, but still not useful information.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: recoll 1.17.3-2
Uname: Linux 4.1.1-040101-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.1
Architecture: amd64
CurrentDesktop: Unity
Date: Fri Jul 10 10:45:04 2015
InstallationDate: Installed on 2015-06-08 (31 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: recoll
UpgradeStatus: Upgraded to vivid on 2015-06-09 (30 days ago)

[Karl-Philipp Richter (krichter722)]

The reason seems to be https://bugs.launchpad.net/ubuntu/+source/recoll/+bug/1473354. This is about the feedback.