Revert "Remove unused method"

This reverts commit c047c9c3d51abbec6ccb59cf76d34f9e4f18495a.

Conflicts:
	src/br/usp/ime/thiagoko/loginuspnet/WifiChangeReceiver.java
Only search for networks with USPNET ssid

Instead of searching for the more generic USP ssid. This should make
less clutter.