Describe the change
Issue with exception logic for scanners with general exceptions converted to str. String slices were being performed on the object rather than the converted str.

Modifies logic to properly convert object to string, followed by a string slice.

Describe testing procedures

...
Step 10/11 : USER 1001
 ---> Running in 01498e092602
Removing intermediate container 01498e092602
 ---> 790a313a5b02
Step 11/11 : ENTRYPOINT ["strelka-frontend"]
 ---> Running in 313cff4d6615
Removing intermediate container 313cff4d6615
 ---> 4412565dc73c
Successfully built 4412565dc73c
Successfully tagged build_frontend:latest
...

Sample output
N/A

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of and tested my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings