prevent multiple attempts to initialise logging

diff --git a/src/jalview/bin/Cache.java b/src/jalview/bin/Cache.java
index cebb504..5688ae1 100755 (executable)
--- a/src/jalview/bin/Cache.java
+++ b/src/jalview/bin/Cache.java
@@ -170,6 +170,10 @@ public class Cache
 
   public static void initLogger()
   {
+    if (log!=null)
+    {
+      return;
+    }
     try
     {
       // TODO: redirect stdout and stderr here in order to grab the output of