Make matchPlayer return only the exact-matched player, if there is one.

By: Animosity <nullcline@gmail.com>

paper-server/src/main/java/org/bukkit/craftbukkit/CraftServer.java

@@ -90,6 +90,7 @@ public final class CraftServer implements Server {
 
             if (partialName.equalsIgnoreCase(iterPlayerName)) {
                 // Exact match
+            	matchedPlayers.clear();
             	matchedPlayers.add(iterPlayer);
             	break;
             }