Fix classical mistake - which is freeing list iterator while iterating it. This causes crash on module interface destruction in some cases.
Fix classical mistake - which is freeing list iterator while
iterating it. This causes crash on module interface destruction
in some cases.

sippy/rtpproxy,dsanders11/rtpproxy,dsanders11/rtpproxy,dsanders11/rtpproxy,sippy/rtpproxy,sippy/rtpproxy