e_alert_main: Don't monitor in E in wayland only mode to avoid endless restarts

When running in Wayland only mode we don't have XCB available so a
xcb_connection would fail and we would restart endlessly.

I have been bitten by that often enough now. Better shutdown E cleanly and don't
use the watchdog functionality for now. This needs a wayland specific solution
anyway.

src/bin/e_alert_main.c

@@ -66,6 +66,12 @@ main(int argc, char **argv)
    const char *tmp;
    int i = 0;
 
+/* XCB is not avaibale when running in wayland only mode. No need to start anything here */
+#ifdef HAVE_WAYLAND_ONLY
+   printf("E Alert is not suitable to be used with E in wayland only mode\n");
+   exit(0);
+#endif
+
    for (i = 1; i < argc; i++)
      {
         if ((!strcmp(argv[i], "-h")) ||