Remove dependency on scrollkeeper

This is obsolete and no longer exists in Debian 10 and Ubuntu 20.04.

Author: clefebvre

debian/control

@@ -14,7 +14,6 @@ Build-Depends:
  , libjpeg-dev
  , libsm-dev
  , libice-dev
- , scrollkeeper
  , automake
  , autoconf
  , libtool
@@ -82,7 +81,6 @@ Architecture: all
 Recommends: yelp
 Depends:
  ${misc:Depends}
- , scrollkeeper
 Description: image viewer and browser - arch-independent files
  Pix is an advanced image viewer and browser. It has many useful
  features, such as filesystem browsing, slide show, image catalogs, web