fixed logger error stacktraces

Author: gnembon

src/main/java/carpet/commands/LogCommand.java

@@ -153,8 +153,7 @@ private static int unsubFromLogger(CommandSource source, String player_name, Str
             Messenger.m(source, "r No player specified");
             return 0;
         }
-        Logger log = LoggerRegistry.getLogger(logname);
-        if (log == null)
+        if (LoggerRegistry.getLogger(logname) == null)
         {
             Messenger.m(source, "r Unknown logger: ","rb "+logname);
             return 0;
@@ -172,6 +171,11 @@ private static int toggleSubscription(CommandSource source, String player_name,
             Messenger.m(source, "r No player specified");
             return 0;
         }
+        if (LoggerRegistry.getLogger(logName) == null)
+        {
+            Messenger.m(source, "r Unknown logger: ","rb "+logName);
+            return 0;
+        }
         boolean subscribed = LoggerRegistry.togglePlayerSubscription(player_name, logName);
         if (subscribed)
         {
@@ -191,6 +195,11 @@ private static int subscribePlayer(CommandSource source, String player_name, Str
             Messenger.m(source, "r No player specified");
             return 0;
         }
+        if (LoggerRegistry.getLogger(logname) == null)
+        {
+            Messenger.m(source, "r Unknown logger: ","rb "+logname);
+            return 0;
+        }
         LoggerRegistry.subscribePlayer(player_name, logname, option);
         if (option!=null)
         {