Change int bLogCmd to extern int bLogCmd

Changes in version 0.56.4 3/20/2021 wd5m

Bug Fixes:

1. Corrected int bLogCmd to be extern int bLogCmd and placed in
   src/conference.h as it is shared between nodes.cpp and conference.c
   now. Changes linkbox/nodes.cpp, src/conference.c and src/conference.h.
   This should resolve issues with some compilers.

Patched EchoLink client talking indicator

Patched to display client talking indicator on EchoLink clients from non EchoLink stations.
See Changelog

Minor update to Debian install script

Added "chmod +x /etc/init.d/tlb" to Debian/install script.

Update to fix memory leak

This update fixes a memory leak issue, as well as adding a few minor enhancements and changes. See the Changelog file for more details.