Some CertificateObjects get created with null store locations

[guyacosta]

Describe the bug
Detected an exception being reported regularly for GUI version of app related to inability to write to certificate table.

To Reproduce
Steps to reproduce the behavior:

1. Go to Scan, run a couple
2. Click on Results to analyze
3. Note captured exception being sent as part of telemetry

Expected behavior
No exceptions reported on normal application use

Screenshots
If applicable, add screenshots to help explain your problem.

System Configuration (please complete the following information):

• OS: [e.g. Windows]
• OS Version: [e.g. Windows 10 1803]
• Application Version: [e.g. 2.0.1-beta+50af283871]
• CLI or GUI:

Additional Context
Add any other context about the problem here.

[gfs]

Should investigate why this is happening. The underlying code is deserializing a CertificateObject, which otherwise should be working fine, so it likely means that either a certificate object was created with a null StoreLocation field, or somehow there's a ghost null result when there are otherwise no results.

[gfs]

Fixed in #116.