Fix a buffer overflow in AL_AddLoopSounds

This fixes a crash in mine4.bsp and most likely some other problems.
The bug was reported by "mxmvasilyev0 [at] gmail [dot] com" and tracked
as Github issue #1.

src/client/sound/snd_al.c

@@ -288,7 +288,7 @@ static channel_t *AL_FindLoopingSound( int entnum, sfx_t *sfx ) {
 
 static void AL_AddLoopSounds( void ) {
     int         i;
-    int         sounds[64]; // 64 is MAX_PACKET_ENTITIES in YQ2 (there's no define for it, though :/)
+    int         sounds[MAX_EDICTS];
     channel_t   *ch;
     sfx_t       *sfx;
     sfxcache_t  *sc;