CommitCommand: Remove declaration of unthrown exception

Change-Id: I1795b1e510ab170f062ee6c5988d7a7567abe260
Signed-off-by: David Pursehouse <david.pursehouse@sonymobile.com>

org.eclipse.jgit/src/org/eclipse/jgit/api/CommitCommand.java

@@ -312,7 +312,7 @@ public class CommitCommand extends GitCommand<RevCommit> {
 		}
 	}
 
-	private void insertChangeId(ObjectId treeId) throws IOException {
+	private void insertChangeId(ObjectId treeId) {
 		ObjectId firstParentId = null;
 		if (!parents.isEmpty())
 			firstParentId = parents.get(0);