In the kmail2 composer, when the entry in the dictionary gets changed and the  flag "sticky" gets checked, kmail will crash the next time the composer gets opened.

Versions:
KMail 5.0.2
KDE Frameworks 5.15.0
Qt 5.4.2 (built against 5.4.2)
on Kubuntu 15.10

Reproducible: Always

Steps to Reproduce:
1. Create new KDE suer and log it in
2. Start KMail
3. Open composer ("New" button)
4. Show the dictionary (Menu View > Dictionary)
5. Change the dictionairy, eg. from American English to Australian English 
6. On the right side behind the dictionary, check the "Sticky" flag
7. Close the composer (no saving required)
8. Open composer ("New" button)
=> Kmail will crash

Actual Results:  
kmail crashes

Expected Results:  
kmail does not crash, selected dictionary gets set as default.


Log:
[...]
log_templateparser: AKONADI PORT: verify Akonadi::Item() here   virtual QString TemplateParser::TemplateParser::findTemplate()
log_templateparser: Identity found: 1393259888
log_messageviewer: Node UNprocessed:  0xa25c00
log_messageviewer: SET NODE:  0xa25c00 true
log_messageviewer: Node processed:  "" "Content-Type: text/plain"
log_templateparser: Command: REM=
log_templateparser: Command: -
log_templateparser: Command: BLANK
log_templateparser: No appropriate charset found.
log_messagecomposer: initalising autosave
No language dictionaries for the language: "en"
No language dictionaries for the language: "en"
No language dictionaries for the language: "en"
No language dictionaries for the language: "en"
No language dictionaries for the language: "en"
log_kmail: 
log_kmail: "Caco3"
No language dictionaries for the language: "en"
*** KMail got signal 11 (Exiting)
Segmentation fault