gnu: duplicity: Update to 0.7.18.

* gnu/packages/backup.scm (duplicity): Update to 0.7.18.

gnu/packages/backup.scm

@@ -67,7 +67,7 @@
 (define-public duplicity
   (package
     (name "duplicity")
-    (version "0.7.17")
+    (version "0.7.18")
     (source
      (origin
       (method url-fetch)
@@ -77,7 +77,7 @@
                           version ".tar.gz"))
       (sha256
        (base32
-        "0jmh3h09680xyf33hzxxxl74bwz66zqhzvjlj7j89r9rz3qwa91p"))))
+        "1qlika4l1k1nx8zr657ihcy0yzr1c1cdnjlbs325l5krvc3zbc5b"))))
     (build-system python-build-system)
     (native-inputs
      `(("util-linux" ,util-linux)       ; setsid command, for the tests
@@ -101,13 +101,13 @@
        (modify-phases %standard-phases
          (add-before 'build 'patch-source
            (lambda* (#:key inputs #:allow-other-keys)
-             ;; embed gpg store name
+             ;; Embed gpg store name.
              (substitute* "duplicity/gpginterface.py"
                (("self.call = 'gpg'")
                 (string-append "self.call = '" (assoc-ref inputs "gnupg") "/bin/gpg'")))
 
              ;; This matches up with an unreleased upstream fix, it should be
-             ;; removed when the package is updated
+             ;; removed when the package is updated.
              ;; https://bazaar.launchpad.net/~duplicity-team/duplicity/0.8-series/revision/1308
              (substitute* "duplicity/gpg.py"
                (("--no-secmem-warning'\\)")