MergeFormatter: Suppress warning about unchecked conversion

The warning can be fixed by adding a type to the argument, but doing so
breaks the API and previous attempts to fix it in that way [1, 2] were
reverted [3, 4].

[1] https://git.eclipse.org/r/#/c/45709/
[2] https://git.eclipse.org/r/#/c/66602/
[3] https://git.eclipse.org/r/#/c/49400/
[4] https://git.eclipse.org/r/#/c/66659/

Change-Id: I01dd52e09da24f70d408ffa96e21c129a79041ea
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

org.eclipse.jgit/src/org/eclipse/jgit/merge/MergeFormatter.java

@@ -102,6 +102,7 @@ public class MergeFormatter {
 	 *            metadata
 	 * @throws IOException
 	 */
+	@SuppressWarnings("unchecked")
 	public void formatMerge(OutputStream out, MergeResult res, String baseName,
 			String oursName, String theirsName, String charsetName) throws IOException {
 		List<String> names = new ArrayList<String>(3);