fsm: use deferred deallocation

Since osmo-bsc uses the MGCP client FSMs, it is required to enable this new
feature to guarantee safe operation. The issue is described in detail in commit
logs linked below.

Depends: Ief4dba9ea587c9b4aea69993e965fbb20fb80e78 (libosmocore),
         I0adc13a1a998e953b6c850efa2761350dd07e03a (libosmocore)
Related: I7df2e9202b04e7ca7366bb0a8ec53cf3bb14faf3 (osmo-mgw)
Change-Id: Ib7fce7b7d54dfb87af97544796680919e5929a50
1 file changed