[1.0.3.80] Incorrect check for water when building routes

[snarko]

In CvPlot::canBuild there's this code:

	if(eRoute != NO_ROUTE)
	{
		if(getRouteType() != NO_ROUTE)
		{
			if (isWater() && !thisBuildInfo.IsWater())
			{
				return false;
			}

			*snip*
		}

		bValid = true;
	}

This is to prevent you from building a route on water if it's supposed to be on land and vice versa. The issue is because it's inside the if(getRouteType() != NO_ROUTE) statement it will only be run if the plot already HAS a route. This allows you to build roads and even railroads on water if you have a worker that can cross it without embarking. Which isn't possible in the base game, but may be possible in mods.