Increase the default thunk array size

This value should be enough to hold IDs for most apps without needing to
reallocate it, while not being unnecessarily large (4KB).

OpenAL32/alThunk.c

@@ -35,7 +35,7 @@ static RWLock ThunkLock;
 void ThunkInit(void)
 {
     RWLockInit(&ThunkLock);
-    ThunkArraySize = 1;
+    ThunkArraySize = 1024;
     ThunkArray = al_calloc(16, ThunkArraySize * sizeof(*ThunkArray));
 }