FIX: Implement the seek in the sdl2 module

src/module/mpv.c

@@ -277,8 +277,11 @@ loop:
 
     /* Can I seek? */
     if (*set_seek >= 0 && *state != STATE_STOP) {
+        if (lmpv_set_position(ctx, *set_seek))
+            LOG_DEBUG("WINDOW", "Failed to seek the mpv context to %s", set_seek);
+        else
+            LOG_DEBUG("WINDOW", "Seeking the mpv context to %s", set_seek);
         *set_seek = -1;
-        LOG_DEBUG("WINDOW", "Ignored set_seek");
     }
 
     /* A loop without indentation. Ugly but better for not-really-wide screens */