MFH: r504791
mail/thunderbird: update to 60.7.2 (release)
Release notes: https://www.thunderbird.net/en-US/thunderbird/60.7.2/releasenotes/
Approved by: gecko@ (jbeich@, implicit)
Security: 49beb00f-a6e1-4a42-93df-9cb14b4c2bee
Approved by: portmgr (blanket: web browser alike)