Description: If a city contains all land pentagon, basically fully surrounded by water, it cannot be attacked by any units. Naval units face message that they cannot besiege a town, but I would expect to be able if its territory touches the water, and land units face error message that they cannot besiege a city while they are in sea. 

Not sure if this intended or not, but I would expect at some way to be able to take over such cities.

Attachments:

Steps to Reproduce:

1. Have a city taking all land pentagons, like in the screenshot (happens in really small islands)

2. Try to attack the city with naval and/or land units 

 - it is not possible

Expected Behavior: Not sure what is the correct for such cities, but I can think of the following options:

1. One option is to auto-resolve such battles, so the units are not actually deployed. May be add some penalty for embarking

2. Allow  naval units to capture such cities that are touching the water.

3. Allow land units to embark such cities once the naval clear the defenders