Steps to reproduce:
1. make /home/whoever/.gnucash/qif-accounts-map readonly
2. Import QIF file and follow druid
3. GNUCash crashes on clicking Apply


Stack trace:
Running with --debug option gives:
*********************
Backtrace:
In unknown file:
   ?: 0* [qif-import:save-map-prefs #(() # # ...) #(# # # ...) ...]
In /usr/share/gnucash/scm/qif-import/qif-guess-map.scm:
 272: 1* (let (#) (with-output-to-file pref-filename #))
 276: 2  [with-output-to-file "/home/karl/.gnucash/qif-accounts-map" ...]
In unknown file:
   ?: 3  (let* ((nport #) (ans #)) (close-port nport) ans)
   ?: 4* [open-output-file "/home/karl/.gnucash/qif-accounts-map"]
   ?: 5  [#<procedure #f #> "/home/karl/.gnucash/qif-accounts-map" "w"]
   ?: 6  [open-file "/home/karl/.gnucash/qif-accounts-map" "w"]
<unnamed port>: In procedure open-file in expression (guile-core-open-file filename (if # # ...)):
<unnamed port>: Permission denied: "/home/karl/.gnucash/qif-accounts-map"
******** end of back trace **********


Other information: