Remove trailing spaces when normalizing Description

… and make carriage-return optional.

src/main/java/de/cronn/jira/sync/mapping/DefaultDescriptionMapper.java

@@ -63,7 +63,7 @@ private String normalizeDescription(String description) {
 		if (description == null) {
 			return null;
 		}
-		return description.replaceAll("\\r\\n", "\n").trim();
+		return description.replaceAll(" *(\\r)?\\n", "\n").trim();
 	}
 
 	public String mapSourceDescription(String sourceDescription, JiraService jiraSource) {