gnu: ‘make-icecat-extension’ inherits package location.

This is an improvement for the purposes of ‘guix edit’ & co.

* gnu/build/icecat-extension.scm (make-icecat-extension): Add ‘location’
field.

Change-Id: I896ae6823b3fe4ea013fa74e2c536f45664d8042

gnu/build/icecat-extension.scm

@@ -29,6 +29,7 @@ when installed, will make the extension contained in PKG available as an
 Icecat browser extension.  PKG-OUTPUT specifies which output of PKG to use."
   (package
     (inherit pkg)
+    (location (package-location pkg))
     (name (string-append (package-name pkg) "-icecat"))
     (native-inputs '())
     (inputs '())