docs: update links to TF-A issues tracker

developer.trustedfirmware.org is deprecated so we cannot use its issues
tracker anymore. Instead, the project will now make use of the issues
tracker associated with the project's Github mirror at [1].

Reflect this change in TF-A documentation.

[1] https://github.com/TrustedFirmware-A/trusted-firmware-a/issues

Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
Change-Id: I912f7dafc74368dba4e61ba4c9f358d5bf8346a9
diff --git a/docs/process/security.rst b/docs/process/security.rst
index c49ca6e..1e7ac2e 100644
--- a/docs/process/security.rst
+++ b/docs/process/security.rst
@@ -76,7 +76,7 @@
 |  |TFV-11| |  A Malformed SDEI SMC can cause out of bound memory read         |
 +-----------+------------------------------------------------------------------+
 
-.. _issue tracker: https://developer.trustedfirmware.org/project/board/1/
+.. _issue tracker: https://github.com/TrustedFirmware-A/trusted-firmware-a/issues
 .. _mailing list: https://lists.trustedfirmware.org/mailman3/lists/tf-a.lists.trustedfirmware.org/
 
 .. |TFV-1| replace:: :ref:`Advisory TFV-1 (CVE-2016-10319)`