commit-template: Remove approval comment for MFH

[fernape]

Summary

There is no need for approval when MFH in ports.
The field just declares one's intentions to merge the change.

Test Plan

• Looks good
• Spell checked
• Use the same imperative tense as before

[0mp]

Actually, I've opened a revision to remove it completely from the src tree hook. See https://reviews.freebsd.org/D29860

[fernape]

Superseded by https://reviews.freebsd.org/D29860