AjcTaskTest: Be more lenient with aspectjrt version warning

Filter out a warning which occurs, if the current release does not match
the stored binary in lib/test:

  bad version number found in aspectjrt.jar
  expected 1.9.21.M1 found 1.9.20.1

If e.g. we run tests for a milestone release a.b.5.M1 and afterwards
switch back to a.b.5-SNAPSHOT, we do not want to update lib/test for a
single commit, just to make this test pass. Hence, we ignore this
warning here.

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

taskdefs/src/test/java/org/aspectj/tools/ant/taskdefs/AjcTaskTest.java

@@ -1021,6 +1021,18 @@ public class AjcTaskTest extends TestCase {
 			IMessage.Kind kind) {
 			if (num != IGNORE) {
 				int actual = holder.numMessages(kind, false);
+
+				// Filter out a warning which occurs, if the current release does not match the stored binary in lib/test.
+				// If e.g. we run tests for a milestone release a.b.5.M1 and afterwards switch back to a.b.5-SNAPSHOT, we do not
+				// want to update lib/test for a single commit, just to make this test pass. Hence, we ignore this warning here.
+				if (kind.equals(IMessage.WARNING)) {
+					for (IMessage message : holder.getMessages(kind, false)) {
+						String warningMessage = message.getMessage();
+						if (warningMessage.matches("bad version number found in .*aspectjrt.jar expected .* found .*"))
+							actual--;
+					}
+				}
+
 				if (num != actual) {
 					if (actual > 0) {
 						MessageUtil.print(