Change boss kill screenshot naming

Change it to use the same formatting used for raids 1/2 and barrows

runelite-client/src/main/java/net/runelite/client/plugins/screenshot/ScreenshotPlugin.java

@@ -352,7 +352,7 @@ public class ScreenshotPlugin extends Plugin
 			{
 				String bossName = m.group(1);
 				String bossKillcount = m.group(2);
-				String fileName = bossName + " kill " + bossKillcount;
+				String fileName = bossName + "(" + bossKillcount + ")";
 				takeScreenshot(fileName);
 			}
 		}