fix mpv version number prefixed with v

[emiltoacs]

In Arch mpv -V returns a version number prefixed with a 'v' letter like : mpv v0.37.0

[kbsky]

The latest mpv has also dropped a number of deprecated aliases, so the following diff is also required for the mpv backend to work:

diff --git a/gmusicbrowser_mpv.pm b/gmusicbrowser_mpv.pm
index 9255a4dd9f0f..ef233b3916ae 100644
--- a/gmusicbrowser_mpv.pm
+++ b/gmusicbrowser_mpv.pm
@@ -101,7 +101,7 @@ sub cmd_shift

 sub launch_mpv
 {  $preparednext=undef;
-   @cmd_and_args=($mpv, '--input-unix-socket='.$SOCK, qw/--idle --no-video --no-input-terminal --really-quiet --gapless-audio=weak --softvol-max=100 --mute=no --no-sub-auto/);
+   @cmd_and_args=($mpv, '--input-ipc-server='.$SOCK, qw/--idle --no-video --no-input-terminal --really-quiet --gapless-audio=weak --volume-max=100 --mute=no --no-sub-auto/);
    push @cmd_and_args,"--volume=".convertvolume($::Volume);
    if ($::Options{use_replaygain})
    {   if(check_version(0,28))

[squentin]

Thanks for reporting this, I removed support for very old versions of mpv too as it's not worth the trouble to keep it.