fix accidentally changed hash of gradle 6.5.1
fix accidentally changed hash of gradle 6.5.1

This was changed in 394ad8f8630b9db1eec74f0410679c9d49c70926 when
deleting 6.6 from makebuildserver but deleting one line up instead of
down.

f-droid/fdroid-server,f-droid/fdroid-server,f-droid/fdroidserver,f-droid/fdroidserver,fdroidtravis/fdroidserver,fdroidtravis/fdroidserver,f-droid/fdroidserver,f-droid/fdroidserver,f-droid/fdroid-server,fdroidtravis/fdroidserver,f-droid/fdroid-server,f-droid/fdroid-server,fdroidtravis/fdroidserver,f-droid/fdroidserver