gnu: opencv: Ignore CVEs.

* gnu/packages/image-processing.scm (opencv)[properties]:  Add a
lint-hidden-cve property and add three CVEs to be ignored.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu/packages/image-processing.scm

@@ -372,6 +372,11 @@ (define-public opencv
               ("protobuf" ,protobuf)
               ("vtk" ,vtk)
               ("python" ,python)))
+    ;; These three CVEs are not a problem of OpenCV, see:
+    ;; https://github.com/opencv/opencv/issues/10998
+    (properties '((lint-hidden-cve . ("CVE-2018-7712"
+                                      "CVE-2018-7713"
+                                      "CVE-2018-7714"))))
     (synopsis "Computer vision library")
     (description "OpenCV is a library aimed at
 real-time computer vision, including several hundred computer