Update extensions version

Signed-off-by: Peter Shipton <[email protected]>

Author: pshipton

closed/autoconf/custom-spec.gmk.in

@@ -82,7 +82,7 @@ COMPILER_VERSION_STRING := @COMPILER_VERSION_STRING@
 
 include $(TOPDIR)/closed/openjdk-tag.gmk
 
-J9JDK_EXT_VERSION       := $(VERSION_NUMBER_FOUR_POSITIONS)
+J9JDK_EXT_VERSION       := 17.0.12.1
 J9JDK_EXT_NAME          := Extensions for OpenJDK for Eclipse OpenJ9
 
 # required by CMake