"Messaging Menu" Thunderbird extension broke Thunderbird v11.0

[Mathieu MD]

After an upgrade to Thunderbird 11.0, its interface is broken; see attached screenshot.

Solution:
- Start Thunderbird with "thunderbird -safe-mode"
- Check "Disable all add-ons"
- Click "Make Changes and Restart"
- Open the Add-ons manager and enable back all modules except "Messaging Menu and Unity Launcher integration 0.9.3".

When "Messaging Menu and Unity Launcher integration 0.9.3" is enabled, launching Thunderbird from the console do report this:
########################################
X Error of failed request: BadRequest (invalid request code or no such operation)
  Major opcode of failed request: 154 (GLX)
  Minor opcode of failed request: 19 (X_GLXQueryServerString)
  Serial number of failed request: 13
  Current serial number in output stream: 13
-- Exception object --
+ QueryInterface (function) 3 lines
+ message (string) 'Component returned failure code: 0x80570016 (NS_ERROR_XPC_GS_RETURNED_FAILURE) [nsIJSCID.getService]'
+ result (number) 2153185302
+ name (string) 'NS_ERROR_XPC_GS_RETURNED_FAILURE'
+ filename (string) 'chrome://messenger/content/search.xml'
+ lineNumber (number) 109
+ columnNumber (number) 0
+ location (object) JS frame :: chrome://messenger/content/search.xml :: :: line 109
+ inner (object) null
+ data (object) null
+ initialize (function) 3 lines
*
########################################