Arduino stacking wifi and gsm shield
You can still use both of them although you'll need to buy another piece to make it work.

This is called the Go-Between Shield and it basically lets you re-route a pin to a different one.  You will need to change the pin number in your code to the one you re-assign that signal to but it will still work.  

The signals you listed that go on that pin are very incompatible, as in if you try to do it, you'll have problems.  Every time your Wifi shield will try to connect to something, your GSM shield will reset.