messages_aspectj.properties: update ECJ version string

This update includes the upstream fix for
https://github.com/eclipse-jdt/eclipse.jdt.core/issues/911.

Eclipse Compiler b15e5c7565 (24Mar2023) - Java20

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

org.aspectj.ajdt.core/src/main/resources/org/aspectj/org/eclipse/jdt/internal/compiler/batch/messages_aspectj.properties

@@ -1,5 +1,5 @@
 compiler.name = AspectJ Compiler
-compiler.version = Eclipse Compiler 40fa81de93d65b (24Mar2023) - Java20
+compiler.version = Eclipse Compiler b15e5c75653358 (24Mar2023) - Java20
 compiler.copyright =
 
 misc.version = {0} {1} - {2} {3}