LogManager: Don't register runtime shutdown hook in router context.

This was causing shutdown() to be called twice, resulting
in lost log messages when stopped from i2prouter.

core/java/src/net/i2p/util/LogManager.java

@@ -150,14 +150,18 @@ public class LogManager implements Flushable {
         // so it doesn't create a log directory and log files unless there is output.
         // In the router context, we have to rotate to a new log file at startup or the logs.jsp
         // page will display the old log.
-        if (context.isRouterContext())
+        if (context.isRouterContext()) {
             startLogWriter();
-        try {
-            Runtime.getRuntime().addShutdownHook(new ShutdownHook());
-        } catch (IllegalStateException ise) {
-            // shutdown in progress, fsck it
+        } else {
+            // Only in App Context.
+            // In Router Context, the router has its own shutdown hook,
+            // and will call our shutdown() from Router.finalShutdown()
+            try {
+                Runtime.getRuntime().addShutdownHook(new ShutdownHook());
+            } catch (IllegalStateException ise) {
+                // shutdown in progress
+            }
         }
-        //System.out.println("Created logManager " + this + " with context: " + context);
     }
 
     /** @since 0.8.2 */