fixed double socket close in rescue

lib/landline/extensions/websocket.rb

@@ -93,7 +93,7 @@ module Landline
       rescue Errno::EPIPE => e
         @writable = false
         _emit :error, e
-        close
+        close if @readable
         nil
       end
 
@@ -210,7 +210,7 @@ module Landline
         end
       rescue Errno::ECONNRESET => e
         _emit :error, e
-        close
+        close if @readable or @writable
         nil
       end
 
@@ -224,7 +224,7 @@ module Landline
         end
       rescue Errno::ECONNRESET => e
         _emit :error, e
-        close
+        close if @readable or @writable
         nil
       end
     end