Closes #1898 - Removing '.jpg' for less stale gravatar

[leo9-py]

Closes #1898

Description

Was able to alleviate the stale Gravatar issue by deleting '.jpg' in the getAvatarUriFromGravatar() function in avatars.ts.

Gravatar now updates faster, current avatar compared to issue's screenshot stale avatar.

Checklist

• I have followed the guidelines in the Contributing document
• My changes follow the coding style of this project
• My changes build without any errors or warnings
• My changes have been formatted and linted
• My changes include any required corresponding changes to the documentation
• My changes have been rebased and squashed to the minimal number (typically 1) of relevant commits
• My changes have a descriptive commit message with a short title, including a Fixes $XXX - or Closes #XXX - prefix to auto-close the issue that your PR addresses

[eamodio]

Thank you for your contribution!