Update for 18.21.0-rc2

.version

-18.21.0-rc1
+18.21.0-rc2

CHANGES.md

-ChangeLogs/ChangeLog-18.21.0-rc1.md
+ChangeLogs/ChangeLog-18.21.0-rc2.md
\ No newline at end of file

ChangeLogs/ChangeLog-18.21.0-rc2.md

+
+Change Log for Release asterisk-18.21.0-rc2
+========================================
+
+Links:
+----------------------------------------
+
+ - [Full ChangeLog](https://downloads.asterisk.org/pub/telephony/asterisk/releases/ChangeLog-18.21.0-rc2.md)  
+ - [GitHub Diff](https://github.com/asterisk/asterisk/compare/18.21.0-rc1...18.21.0-rc2)  
+ - [Tarball](https://downloads.asterisk.org/pub/telephony/asterisk/asterisk-18.21.0-rc2.tar.gz)  
+ - [Downloads](https://downloads.asterisk.org/pub/telephony/asterisk)  
+
+Summary:
+----------------------------------------
+
+- logger: Fix linking regression.
+
+User Notes:
+----------------------------------------
+
+
+Upgrade Notes:
+----------------------------------------
+
+
+Closed Issues:
+----------------------------------------
+
+  - #539: [bug]: Existence of logger.xml causes linking failure
+
+Commits By Author:
+----------------------------------------
+
+- ### Naveen Albert (1):
+  - logger: Fix linking regression.
+
+
+Detail:
+----------------------------------------
+
+- ### logger: Fix linking regression.
+  Author: Naveen Albert  
+  Date:   2024-01-16  
+
+  Commit 008731b0a4b96c4e6c340fff738cc12364985b64
+  caused a regression by resulting in logger.xml
+  being compiled and linked into the asterisk
+  binary in lieu of logger.c on certain platforms
+  if Asterisk was compiled in dev mode.
+
+  To fix this, we ensure the file has a unique
+  name without the extension. Most existing .xml
+  files have been named differently from any
+  .c files in the same directory or did not
+  pose this issue.
+
+  channels/pjsip/dialplan_functions.xml does not
+  pose this issue but is also being renamed
+  to adhere to this policy.
+
+  Resolves: #539
+