Deleting custom image for project avatar will cause NPE for Edit Project

Deleting custom image for project avatar will cause NPE for Edit Project.

java.lang.NullPointerException
	at com.atlassian.jira.web.action.project.EditProject.doDefault(EditProject.java:67)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at webwork.util.InjectionUtils$DefaultInjectionImpl.invoke(InjectionUtils.java:70)
	at webwork.util.InjectionUtils.invoke(InjectionUtils.java:56)

Steps to reproduce:

1. Create a project
2. Click on Edit for the project from projects list in administration - https://<domain>/secure/project/ViewProjects.jspa
3. Click select image - upload a custom image for avatar and update/save
4. Edit the project again by clicking Edit in project list and select image
5. Delete the custom image by hovering the cursor on it and click X at the top right of the image. Close the select image dialogue
6. Click Update
7. The project avatar now is changed to Atlassian's Charlie instead of default rocket or broken image in project's administration page. Editing the project will throw NPE error

Expected behavior
The project's avatar should be set to default one(rocket icon).

Workaround
The project's avatar ID need to be updated from database and restart JIRA. For Atlassian OnDemand users, please create a support ticket at https://support.atlassian.com under OnDemand Support project to get this fixed.