add info about default gin instance to set it up again if there are problems

initiation_scripts/OSX-SFB1315-portal-initialisation.command

@@ -4,6 +4,9 @@
 # add server, named hu
 gin add-server --web https://gindata.biologie.hu-berlin.de:443 --git git@gindata.biologie.hu-berlin.de:10022 hu
 
+# if anything goes wrong, you may need to readd the gin default server:
+# gin add-server --web https://gin.g-node.org:443 --git git@gin.g-node.org:22 gin
+
 # chose hu server for this computer
 gin use-server hu