Update protonmail-bridge to 1.5.7

Summary:
Summarized Changelog:

• 1.5.7
  • Fixed sending error caused by inconsistent use of upper and lower case in sender’s email address
• 1.5.6
  • Improvements to message parsing
  • Better error handling
  • Fixed sending messages from aliases in combined inbox mode

Test Plan: Synced and send mail in Thunderbird.

Reviewers: Triage Team, JoshStrobl

Reviewed By: Triage Team, JoshStrobl

Subscribers: JoshStrobl

Differential Revision: https://dev.getsol.us/D10443