prevent corrupt messages from breaking messenger loading

core/src/main/groovy/com/muwire/core/messenger/Messenger.groovy

@@ -123,6 +123,7 @@ class Messenger {
         Files.walk(file.toPath())
             .filter({it.getFileName().toString().endsWith(".mwmessage")})
             .forEach { Path path ->
+                try {
                     File f = path.toFile()
                     MWMessage message
                     f.withInputStream {
@@ -131,6 +132,9 @@ class Messenger {
                     addMessage(message, dest)
                     File unread = new File(file, deriveUnread(message))
                     eventBus.publish(new MessageLoadedEvent(message: message, folder: folder, unread: unread.exists()))
+                } catch (IOException iox) {
+                    log.warning("couldn't load message from $path" )
+                }
         }
     }