DoxyGen: Fix broken link to SysTick documentation.
Link from RTOS documentation to Core part was still
pointing to an outdated URL.
@@ -671,7 +671,7 @@ CMSIS-RTOS RTX uses the following \#defines.
\section KernelTimer RTX Kernel Timer Tick and Thread Management
By default, CMSIS-RTOS RTX uses the Cortex-M
-<a href="https://www.keil.com/support/man/docs/gsac/GSAC_SYSTICKtimer.htm" target="_blank">SysTick</a> timer to generate
+<a href="../../Core/html/group__SysTick__gr.html" target="_blank">SysTick</a> timer to generate
periodic interrupts for the RTX kernel timer tick. CMSIS-RTOS provides \ref CMSIS_RTOS_TimerMgmt functions and several
CMSIS-RTOS functions have a timeout parameter. This periodic RTX kernel timer tick interrupt is used to derive the required
time interval. CMSIS-RTOS RTX also provides configuration options for a alternative timer and tick-less operation. Refer to
