Revert: alsactl: Only start restore service when asoundrc file exists

Adding the alsactl state file as condition for the service to start causes the issue that it never starts if the ALSA state is not stored manually once. For the service to create the state file, it needs to start to then call ExecStop and create the state file. The very first "alsactl restore", when no state file exists (yet) will fail, but "ExecStart=-" (the dash) allows the systemd unit to keep active state to exit with "alsactl store" which creates the state file.

Commit that is to be reverted: f1eba0b5

This issue has been reported here: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=925455 1.1.8-2 was aimed to be a fix but caused new issues: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=932209 1.1.8-3 fixed the issues caused by 1.1.8-2, including the removal of the alsactl state file from alsa-restore.service, but that revert is not reflected in any Git repository I could find. Hence this MR to create a match between repository and downstream package code.