This changes how we create the temporary directory /run/freeswitch
when starting FS with systemd.  The /run directory starts empty after
a system reboot, so we need to ensure this directory is present.

Originally for the FS systemd unit we created /run/freeswitch using
ExecStartPre and mkdir.  With commit adb5f0d2 this was changed to use
the tmpfiles.d(5) mechanism (but the ExecStartPre/mkdir code was not
removed).

As part of systemd.exec(5), systemd provides a mechanism to
automatically manage these directories under /run and to bind their
lifetime to the lifetime of the process.  This is actually what we
want here as compared to the more general tmpfiles.d(5) mechanism.

This commit moves to using the RuntimeDirectory= mechanism and removes
the obsolete ExecStartPre/mkdir code.

References-commit: adb5f0d2

Merge pull request #502 in FS/freeswitch from ~SAUMAR/freeswitch:bugfix/FS-7673-odbc-null-value-incorrectly-evaluated to master

* commit '3aa051e1':
  FS-7673: ODBC NULL value incorrectly evaluated in mod_v8

FS-8190 #resolve [When using nixevent, freeswitch stops sending us certain custom event that were NOT part of the nixevent command]

Merge pull request #493 in FS/freeswitch from feature/FS-8042-store-sip-endpoint-ping-response to master

* commit '5509a627':
  FS-8042, FS-8182: add ping time (in ms) to sip_registrations table, displays as part of the show commands that show registration details, add force_ping=true user var to force options ping on individual registered endpoints

Merge pull request #498 in FS/freeswitch from ~STEFAN_YOHANSSON/freeswitch:bugfix/FS-8095-add-factory-reset-to-settings to master

* commit 'bc4d21e3':
  FS-8095 [verto_communicator] added reset button to default settings.

FS-8042, FS-8182: add ping time (in ms) to sip_registrations table, displays as part of the show commands that show registration details, add force_ping=true user var to force options ping on individual registered endpoints

This reverts commit 5bf0d834.

FS-8130 don't skip delta on video unless it was less than 1 second worth to prevent locking up chrome

Merge pull request #490 in FS/freeswitch from ~STEFAN_YOHANSSON/freeswitch:bugfix/FS-8146-long-names-breaks-member-list to master

* commit 'cf7cdb25':
  FS-8146 - [verto_communicator] fix loong names in members list

Merge pull request #488 in FS/freeswitch from ~STEFAN_YOHANSSON/freeswitch:bugfix/FS-8155-uuid_kill-or-fsctl-hupall-to-kill to master

* commit 'eefeaa6a':
  FS-8155 - [verto_communicator] check for nulled data.liveArray preventing locked video interface

FS-8185: [core] Allow xml preprocessor to expand variables where the resulting value is much longer than the original size

* commit 'fbacd42c':
  FS-5660 - add freeswitch.py to the freeswitch-mod-python debian package

Merge pull request #451 in FS/freeswitch from ~DRAGOS_OANCEA/freeswitch-dragos:opus_repacketize_refactor to master

* commit '753213b7':
  FS-8080: mod_opus: fine-tune FEC with repacketization (ptimes: 80 ms,100 ms,120 ms)

Merge pull request #486 in FS/freeswitch from ~DRAGOS_OANCEA/freeswitch-dragos:opus-decode-has_fec-test to master

* commit 'de67b09e':
  FS-8179: mod_opus:  improve JB debugging with FEC