Reverted unjffs2.py

src/binwalk/plugins/unjffs2.py

 # This file has been depreciated and is no longer in use.
 # This is merely a placeholder to ensure future installations
 # don't leave the old, depreciated file in tact.
+
+import binwalk.core.plugin
+
+class Unjffs2DepreciatedPlugin(binwalk.core.plugin.Plugin):
+    pass