MINOR: stconn/applet: Handle EOS in the applet .wake callback function

Just like for end of input, the end of stream reported by the endpoint
(SE_FL_EOS flag) is now handled in sc_applet_process(). The idea is to have
applets acting as muxes by reporting events through the SE descriptor, as
far as possible.

src/stconn.c

@@ -1829,6 +1829,11 @@ static int sc_applet_process(struct stconn *sc)
 		ic->flags |= (CF_EOI|CF_READ_EVENT);
 	}
 
+	if (sc_ep_test(sc, SE_FL_EOS)) {
+		/* we received a shutdown */
+		sc_shutr(sc);
+	}
+
 	/* If the applet wants to write and the channel is closed, it's a
 	 * broken pipe and it must be reported.
 	 */