[client] disable multisample after logo is gone

We only use multisample to smooth out the edges of the LG logo, it is
pointless to leave it on after the logo is gone.

client/renderers/opengl.c

@@ -662,6 +662,7 @@ static void render_wait(struct Inst * this)
     uint64_t t = microtime();
     if (t > this->waitFadeTime)
     {
+      glDisable(GL_MULTISAMPLE);
       this->waitDone = true;
       return;
     }