haskellPackages: pager -> desktop-pager

Rename pager to desktop-pager to prevent a name clash with
https://hackage.haskell.org/package/pager, causing hledger-lib to not
build.

krebs/5pkgs/haskell/desktop-pager.nix

@@ -4,7 +4,7 @@
 , utf8-string, X11
 }:
 mkDerivation {
-  pname = "pager";
+  pname = "desktop-pager";
   version = "1.0.0";
   src = fetchgit {
     url = "https://cgit.krebsco.de/pager";

krebs/5pkgs/simple/pager.nix

@@ -33,7 +33,7 @@ pkgs.symlinkJoin {
           -ti vt340 \
           -xrm '*geometry: 32x10' \
           -xrm '*internalBorder: 2' \
-          -e ${pkgs.haskellPackages.pager}/bin/pager "$@"
+          -e ${pkgs.haskellPackages.desktop-pager}/bin/pager "$@"
     '')
     pkgs.haskellPackages.pager
   ];