%gall diff spec fix
`%gall` was unnecessarily specializing diff types.
::
++ ap-diff :: pour a diff
|= {her/ship pax/path cag/cage}
- =. q.cag (spec q.cag)
+ :: =. q.cag (spec q.cag)
=+ cug=(ap-find [%diff p.cag +.pax])
?~ cug
%. [| her +.pax]
