Default timeouts changed

The default timeout of 2000ms was a bit short. Especially when used in
far away places, thinks work better if these timeouts are set to a much
longer time (e.g. 12000 ms). It doesn't do much harm, when the response
comes quicker the program will continue anyway.
Revert "Default timeouts changed"

This reverts commit 99b27ae876f96f255b5e5ddd4ea46fddad725397.
Default timeouts changed

The default timeouts for the GPRSbee commands changed from 2000 to 4000
ms.