fix create_if_deleted logic by closing the file handle, fix #81

Author: Lucas Pires

lib/logstash/outputs/file.rb

@@ -246,8 +246,8 @@ def open(path)
 
     if deleted?(path)
       if @create_if_deleted
-        @logger.debug("Required path was deleted, creating the file again", :path => path)
-        @files.delete(path)
+        @logger.debug("Required path was deleted, creating the file again, and releasing old handle", :path => path)
+        @files.delete(path).close if cached?(path)
       else
         return @files[path] if cached?(path)
       end