[Bug 34814] unpatch target missing in dpatch.mk

[Lucas Nussbaum]

Public bug reported:
https://launchpad.net/malone/bugs/34814

Affects: cdbs (Ubuntu)
       Severity: Normal
       Priority: (none set)
         Status: Unconfirmed

Description:
Hi,

Could you please consider merging a recent Debian version, or
backporting the fix to Debian bug #284231 (it's a one-liner) ?

This bug prevents librmagick-ruby from building.

Thank you,