Revert "dropbox-cli: minor refactoring to play nice with dropbox"

Undo changes from PR #14077

It's not acceptable to just willy-nilly rename a CLI script. Also, that
PR broke the tray icon for dropbox.

This reverts commit afa4a27a25.

pkgs/applications/networking/dropbox-cli/default.nix

@@ -16,7 +16,8 @@ stdenv.mkDerivation {
   phases = "unpackPhase installPhase";
 
   installPhase = ''
-    mkdir -p "$out/bin/"
+    mkdir -p "$out/bin/" "$out/share/applications"
+    cp data/dropbox.desktop "$out/share/applications"
     substitute "dropbox.in" "$out/bin/dropbox" \
       --replace '@PACKAGE_VERSION@' ${version} \
       --replace '@DESKTOP_FILE_DIR@' "$out/share/applications" \
@@ -24,7 +25,6 @@ stdenv.mkDerivation {
       --replace '@IMAGEDATA64@' '"too-lazy-to-fix"'
     sed -i 's:db_path = .*:db_path = "${dropboxd}":' $out/bin/dropbox
     chmod +x "$out/bin/"*
-    mv $out/bin/dropbox $out/bin/dropbox-cli
     patchShebangs "$out/bin"
   '';