Fix null pointer exception of assignment processing status

[sibinhho99]

Description

In the current code, the forked process for Java engine in https://github.com/WING-NUS/SSID/blob/02d553a8dd482b41f40725f06c5ab9ce628012ff/lib/submissions_handler.rb#L204 might access the SubmissionSimilarityProcess object before its initialization in https://github.com/WING-NUS/SSID/blob/02d553a8dd482b41f40725f06c5ab9ce628012ff/lib/submissions_handler.rb#L237, causing null pointer exception. I changed this initialization to before the forking.

Related Issue

390

Motivation and Context

Bug fix

How Has This Been Tested?

Local testing

Screenshots (if appropriate):

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.

[sibinhho99]

Not yet resolved