Revert "music: replace Spotify by Deezer"

This reverts commit 4af98c2589. I feel
like they should provide a native client for Linux instead of relying
upon the community. MellowPlayer is unmaintained and does not have an
offline mode. Deezer seems the only streaming service with a Linux
client.

bin/i3-companion

@@ -45,7 +45,6 @@ application_icons = {
     "chromium": icon(3, ""),
     "d-feet": icon(2, ""),
     "darktable": icon(2, ""),
-    "deezer": icon(3, ""),
     "discord": icon(3, ""),
     "draw.io": icon(2, ""),
     "easyeffects": icon(2, ""),
@@ -62,7 +61,6 @@ application_icons = {
     "jitsi meet": icon(2, ""),
     "libreoffice": icon(2, "📄"),
     "mednafen": icon(2, ""),
-    "mellowplayer3": icon(3, ""),
     "mpv": icon(2, ""),
     "nestopia": icon(2, ""),
     "org.gnome.maps": icon(2, ""),