hangs on start if remembered directory not available

[rduke15]

Ubuntu 16.04.4 LTS
krusader 1:2.4.0~beta3-2ubuntu1 amd64

When Krusader starts, it tries to open the last directories it had active in the panels when it was last closed.

If one of these directories is not accessible any more, it hangs with an empty window (which turns grey after a few seconds). It then has to be killed with "Force quit" or kill.

This is an example diff of the krusaderrc file, where "/net/afdisk" was an NFS share mounted through autofs, which is not accessible anymore today.

--- ~/.kde/share/config/krusaderrc 2018-04-01 15:12:14.860621817 +0200
+++ ~/.kde/share/config/krusaderrc.bad 2018-04-01 15:11:40.404295063 +0200
@@ -188,7 +188,7 @@
 [Startup][Left Tab Bar][Tabs][Tab1]
 Properties=0
 Type=0
-Url=/
+Url=/net/afdisk/volume1/backups

 [Startup][Left Tab Bar][Tabs][Tab1][History]
 CurrentIndex=0

Krusader should detect that it hangs waiting for a dead network share and revert to a local directory.