server: When possible, use tgkill instead of tkill syscall on Linux.
diff --git a/server/ptrace.c b/server/ptrace.c
index e4cf889..d7134f2 100644
--- a/server/ptrace.c
+++ b/server/ptrace.c
@@ -187,7 +187,7 @@
     {
         if (thread->unix_tid != -1)
         {
-            ret = tkill( thread->unix_tid, sig );
+            ret = tkill( thread->unix_pid, thread->unix_tid, sig );
             if (ret == -1 && errno == ENOSYS) ret = kill( thread->unix_pid, sig );
         }
         else ret = kill( thread->unix_pid, sig );