Reverted to catching Throwable for the netty native epoll stuff.

Change-Id: I41cf621505cdcc3139fadb39a4ccacfe0123ef5c
diff --git a/utils/netty/src/main/java/org/onlab/netty/NettyMessagingManager.java b/utils/netty/src/main/java/org/onlab/netty/NettyMessagingManager.java
index f550498..8d567eb 100644
--- a/utils/netty/src/main/java/org/onlab/netty/NettyMessagingManager.java
+++ b/utils/netty/src/main/java/org/onlab/netty/NettyMessagingManager.java
@@ -102,7 +102,7 @@
             serverChannelClass = EpollServerSocketChannel.class;
             clientChannelClass = EpollSocketChannel.class;
             return;
-        } catch (Exception e) {
+        } catch (Throwable e) {
             log.warn("Failed to initialize native (epoll) transport. Reason: {}. Proceeding with nio.", e.getMessage());
         }
         clientGroup = new NioEventLoopGroup();