Disallow changing the type of an existing BTS from the vty

Changing the BTS type is not supported, so don't allow it.

For example, Changing from type sysmobts to type rbs2000
may hit an OSMO_ASSERT in om2k_bts_fsm_alloc()

The default BTS type if osmo-bsc is started with an empty
configuration and the operator issues config terminal->network->bts 0
will be "unknown". This type and only this type can be
changed from the vty config node.

Change-Id: I0df97ef128a1bbd84c787654d1d842dce4dad819
2 files changed