Merge pull request #1753 in FS/freeswitch from bugfix/FS-11946-fix-possible-unallocated-memory-access to master

* commit 'f9a03570':
  FS-11946: [Core] Fix possible unallocated memory access.

* commit 'cbc36d05':
  FS-11943 [mod_http_cache] Fix typos in warning message in aws.c

FS-11750: JB fix: avoid infinite loop when chan var rtp_nack_buffer_size is small (initial max_packet_len)

(thanks Sergey Hripchenko)

otherwise it complains: [8:Invalid parameter:Profile > 1 not supported in this build configuration]

FS-11926: rename chan var to 'execute_on_fax_close_detect' to prevent it collide with 'execute_on_fax_detect'
(switch_channel_execute_on() would have run them both)

FS-11841 [core] The ts of received rtp packages for DTMF is same. so add SFF_RFC2833 flag check when write rtp package.