Transaction still listed as 'pending' after 12 hours I'm using Electrum 2.5.4 on Tails 2.2.1

Sent the following transaction over 12 hours ago with 0.0005 BTC/kB transaction fee. 

There's a warning message saying the transaction has a none standard input - which after googling doesn't seem to have a concensus on what to do about this

What gives? Any help much appreciated

https://blockchain.info/tx/22e6190880cb2433fb99f27e7daf1a763c5e86d64fadb40b708be8295283a052
The higher the number of unconfirmed transactions (in the mempool) the longer will take to confirm your transaction unless you give a higher fee.

I recommend watching current mempool where you can see the number of unconfirmed transactions and it gives you an idea how "clogged up" is the Bitcoin network.

Unconfirmed transaction will either confirm or expire (not sure but I think it takes 3 days to expire).