gravatar eleminates leading 0 from md5 hash

[ambition-consulting]

Describe the bug
one of my emails is j.cunliffe@extern.deutsche-glasfaser.de - which gets hashed to 0150940e5eeca5fb73bce3f98a072905

doctoolchain produces this link out of it:
image:https://www.gravatar.com/avatar/150940e5eeca5fb73bce3f98a072905?d=identicon[height=32,width=32,role='gravatar',alt='John Cunliffe',title='John Cunliffe']

which is missing the 0 and thus doesn't work: https://www.gravatar.com/avatar/150940e5eeca5fb73bce3f98a072905?d=identicon

To Reproduce
Steps to reproduce the behavior:

1. use my name in commits as email name
2. create contributor snippeys
3. generate site
4. See error

tested on newest version today.