now checks for $DISPLAY before attempting to use GUI

Rev: bin/install.pike:1.63

bin/install.pike

@@ -979,9 +979,14 @@ int pre_install(array(string) argv)
       catch  {
 	if(!no_gui)
 	{
+#ifndef __NT__ /* We are using GTK on Win32!! no DISPLAY required */
+	  if(getenv("DISPLAY"))
+#endif
+	  {
 	    begin_wizard(argv);
 	    return -1; 
 	  }
+	}
       };
 #endif