multimedia/qmmp-qt5: update to 1.6.4 release (+)

Qmmp 1.6.4 have been released

Changes since 1.6.3:

added projectM 4.0 support (experimental);
fixed command execution under Windows in the file operations plugin;
fixed removing of the current playing file in the file operations plugin;
fixed crash on streams in the lyrics plugin;
fixed issues with visualization windows on application startup.